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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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662ce1dc9c
Delay accounting does not track the delay of write-protect copy. When tasks trigger many write-protect copys(include COW and unsharing of anonymous pages[1]), it may spend a amount of time waiting for them. To get the delay of tasks in write-protect copy, could help users to evaluate the impact of using KSM or fork() or GUP. Also update tools/accounting/getdelays.c: / # ./getdelays -dl -p 231 print delayacct stats ON listen forever PID 231 CPU count real total virtual total delay total delay average 6247 1859000000 2154070021 1674255063 0.268ms IO count delay total delay average 0 0 0ms SWAP count delay total delay average 0 0 0ms RECLAIM count delay total delay average 0 0 0ms THRASHING count delay total delay average 0 0 0ms COMPACT count delay total delay average 3 72758 0ms WPCOPY count delay total delay average 3635 271567604 0ms [1] commit 31cc5bc4af70("mm: support GUP-triggered unsharing of anonymous pages") Link: https://lkml.kernel.org/r/20220409014342.2505532-1-yang.yang29@zte.com.cn Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Jiang Xuexin <jiang.xuexin@zte.com.cn> Reviewed-by: Ran Xiaokai <ran.xiaokai@zte.com.cn> Reviewed-by: wangyong <wang.yong12@zte.com.cn> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
7261 lines
199 KiB
C
7261 lines
199 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Generic hugetlb support.
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* (C) Nadia Yvette Chambers, April 2004
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*/
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#include <linux/list.h>
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/seq_file.h>
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#include <linux/sysctl.h>
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#include <linux/highmem.h>
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#include <linux/mmu_notifier.h>
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#include <linux/nodemask.h>
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#include <linux/pagemap.h>
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#include <linux/mempolicy.h>
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#include <linux/compiler.h>
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#include <linux/cpuset.h>
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#include <linux/mutex.h>
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#include <linux/memblock.h>
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#include <linux/sysfs.h>
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#include <linux/slab.h>
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#include <linux/sched/mm.h>
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#include <linux/mmdebug.h>
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#include <linux/sched/signal.h>
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#include <linux/rmap.h>
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#include <linux/string_helpers.h>
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#include <linux/swap.h>
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#include <linux/swapops.h>
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#include <linux/jhash.h>
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#include <linux/numa.h>
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#include <linux/llist.h>
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#include <linux/cma.h>
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#include <linux/migrate.h>
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#include <linux/nospec.h>
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#include <linux/delayacct.h>
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#include <asm/page.h>
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#include <asm/pgalloc.h>
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#include <asm/tlb.h>
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#include <linux/io.h>
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#include <linux/hugetlb.h>
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#include <linux/hugetlb_cgroup.h>
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#include <linux/node.h>
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#include <linux/page_owner.h>
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#include "internal.h"
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#include "hugetlb_vmemmap.h"
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int hugetlb_max_hstate __read_mostly;
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unsigned int default_hstate_idx;
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struct hstate hstates[HUGE_MAX_HSTATE];
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#ifdef CONFIG_CMA
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static struct cma *hugetlb_cma[MAX_NUMNODES];
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static unsigned long hugetlb_cma_size_in_node[MAX_NUMNODES] __initdata;
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static bool hugetlb_cma_page(struct page *page, unsigned int order)
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{
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return cma_pages_valid(hugetlb_cma[page_to_nid(page)], page,
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1 << order);
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}
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#else
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static bool hugetlb_cma_page(struct page *page, unsigned int order)
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{
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return false;
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}
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#endif
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static unsigned long hugetlb_cma_size __initdata;
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/*
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* Minimum page order among possible hugepage sizes, set to a proper value
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* at boot time.
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*/
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static unsigned int minimum_order __read_mostly = UINT_MAX;
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__initdata LIST_HEAD(huge_boot_pages);
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/* for command line parsing */
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static struct hstate * __initdata parsed_hstate;
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static unsigned long __initdata default_hstate_max_huge_pages;
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static bool __initdata parsed_valid_hugepagesz = true;
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static bool __initdata parsed_default_hugepagesz;
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static unsigned int default_hugepages_in_node[MAX_NUMNODES] __initdata;
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/*
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* Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages,
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* free_huge_pages, and surplus_huge_pages.
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*/
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DEFINE_SPINLOCK(hugetlb_lock);
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/*
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* Serializes faults on the same logical page. This is used to
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* prevent spurious OOMs when the hugepage pool is fully utilized.
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*/
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static int num_fault_mutexes;
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struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp;
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/* Forward declaration */
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static int hugetlb_acct_memory(struct hstate *h, long delta);
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static inline bool subpool_is_free(struct hugepage_subpool *spool)
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{
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if (spool->count)
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return false;
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if (spool->max_hpages != -1)
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return spool->used_hpages == 0;
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if (spool->min_hpages != -1)
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return spool->rsv_hpages == spool->min_hpages;
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return true;
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}
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static inline void unlock_or_release_subpool(struct hugepage_subpool *spool,
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unsigned long irq_flags)
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{
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spin_unlock_irqrestore(&spool->lock, irq_flags);
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/* If no pages are used, and no other handles to the subpool
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* remain, give up any reservations based on minimum size and
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* free the subpool */
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if (subpool_is_free(spool)) {
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if (spool->min_hpages != -1)
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hugetlb_acct_memory(spool->hstate,
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-spool->min_hpages);
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kfree(spool);
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}
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}
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struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages,
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long min_hpages)
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{
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struct hugepage_subpool *spool;
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spool = kzalloc(sizeof(*spool), GFP_KERNEL);
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if (!spool)
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return NULL;
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spin_lock_init(&spool->lock);
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spool->count = 1;
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spool->max_hpages = max_hpages;
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spool->hstate = h;
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spool->min_hpages = min_hpages;
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if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) {
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kfree(spool);
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return NULL;
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}
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spool->rsv_hpages = min_hpages;
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return spool;
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}
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void hugepage_put_subpool(struct hugepage_subpool *spool)
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{
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unsigned long flags;
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spin_lock_irqsave(&spool->lock, flags);
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BUG_ON(!spool->count);
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spool->count--;
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unlock_or_release_subpool(spool, flags);
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}
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/*
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* Subpool accounting for allocating and reserving pages.
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* Return -ENOMEM if there are not enough resources to satisfy the
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* request. Otherwise, return the number of pages by which the
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* global pools must be adjusted (upward). The returned value may
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* only be different than the passed value (delta) in the case where
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* a subpool minimum size must be maintained.
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*/
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static long hugepage_subpool_get_pages(struct hugepage_subpool *spool,
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long delta)
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{
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long ret = delta;
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if (!spool)
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return ret;
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spin_lock_irq(&spool->lock);
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if (spool->max_hpages != -1) { /* maximum size accounting */
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if ((spool->used_hpages + delta) <= spool->max_hpages)
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spool->used_hpages += delta;
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else {
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ret = -ENOMEM;
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goto unlock_ret;
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}
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}
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/* minimum size accounting */
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if (spool->min_hpages != -1 && spool->rsv_hpages) {
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if (delta > spool->rsv_hpages) {
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/*
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* Asking for more reserves than those already taken on
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* behalf of subpool. Return difference.
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*/
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ret = delta - spool->rsv_hpages;
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spool->rsv_hpages = 0;
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} else {
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ret = 0; /* reserves already accounted for */
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spool->rsv_hpages -= delta;
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}
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}
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unlock_ret:
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spin_unlock_irq(&spool->lock);
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return ret;
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}
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/*
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* Subpool accounting for freeing and unreserving pages.
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* Return the number of global page reservations that must be dropped.
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* The return value may only be different than the passed value (delta)
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* in the case where a subpool minimum size must be maintained.
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*/
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static long hugepage_subpool_put_pages(struct hugepage_subpool *spool,
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long delta)
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{
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long ret = delta;
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unsigned long flags;
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if (!spool)
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return delta;
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spin_lock_irqsave(&spool->lock, flags);
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if (spool->max_hpages != -1) /* maximum size accounting */
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spool->used_hpages -= delta;
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/* minimum size accounting */
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if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) {
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if (spool->rsv_hpages + delta <= spool->min_hpages)
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ret = 0;
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else
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ret = spool->rsv_hpages + delta - spool->min_hpages;
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spool->rsv_hpages += delta;
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if (spool->rsv_hpages > spool->min_hpages)
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spool->rsv_hpages = spool->min_hpages;
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}
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/*
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* If hugetlbfs_put_super couldn't free spool due to an outstanding
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* quota reference, free it now.
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*/
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unlock_or_release_subpool(spool, flags);
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return ret;
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}
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static inline struct hugepage_subpool *subpool_inode(struct inode *inode)
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{
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return HUGETLBFS_SB(inode->i_sb)->spool;
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}
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static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma)
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{
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return subpool_inode(file_inode(vma->vm_file));
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}
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/* Helper that removes a struct file_region from the resv_map cache and returns
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* it for use.
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*/
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static struct file_region *
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get_file_region_entry_from_cache(struct resv_map *resv, long from, long to)
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{
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struct file_region *nrg = NULL;
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VM_BUG_ON(resv->region_cache_count <= 0);
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resv->region_cache_count--;
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nrg = list_first_entry(&resv->region_cache, struct file_region, link);
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list_del(&nrg->link);
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nrg->from = from;
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nrg->to = to;
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return nrg;
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}
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static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg,
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struct file_region *rg)
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{
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#ifdef CONFIG_CGROUP_HUGETLB
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nrg->reservation_counter = rg->reservation_counter;
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nrg->css = rg->css;
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if (rg->css)
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css_get(rg->css);
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#endif
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}
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/* Helper that records hugetlb_cgroup uncharge info. */
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static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg,
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struct hstate *h,
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struct resv_map *resv,
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struct file_region *nrg)
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{
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#ifdef CONFIG_CGROUP_HUGETLB
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if (h_cg) {
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nrg->reservation_counter =
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&h_cg->rsvd_hugepage[hstate_index(h)];
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nrg->css = &h_cg->css;
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/*
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* The caller will hold exactly one h_cg->css reference for the
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* whole contiguous reservation region. But this area might be
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* scattered when there are already some file_regions reside in
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* it. As a result, many file_regions may share only one css
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* reference. In order to ensure that one file_region must hold
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* exactly one h_cg->css reference, we should do css_get for
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* each file_region and leave the reference held by caller
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* untouched.
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*/
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css_get(&h_cg->css);
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if (!resv->pages_per_hpage)
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resv->pages_per_hpage = pages_per_huge_page(h);
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/* pages_per_hpage should be the same for all entries in
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* a resv_map.
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*/
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VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h));
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} else {
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nrg->reservation_counter = NULL;
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nrg->css = NULL;
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}
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#endif
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}
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static void put_uncharge_info(struct file_region *rg)
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{
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#ifdef CONFIG_CGROUP_HUGETLB
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if (rg->css)
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css_put(rg->css);
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#endif
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}
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static bool has_same_uncharge_info(struct file_region *rg,
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struct file_region *org)
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{
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#ifdef CONFIG_CGROUP_HUGETLB
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return rg->reservation_counter == org->reservation_counter &&
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rg->css == org->css;
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#else
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return true;
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#endif
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}
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static void coalesce_file_region(struct resv_map *resv, struct file_region *rg)
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{
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struct file_region *nrg = NULL, *prg = NULL;
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prg = list_prev_entry(rg, link);
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if (&prg->link != &resv->regions && prg->to == rg->from &&
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has_same_uncharge_info(prg, rg)) {
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prg->to = rg->to;
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list_del(&rg->link);
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put_uncharge_info(rg);
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kfree(rg);
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rg = prg;
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}
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nrg = list_next_entry(rg, link);
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if (&nrg->link != &resv->regions && nrg->from == rg->to &&
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has_same_uncharge_info(nrg, rg)) {
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nrg->from = rg->from;
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list_del(&rg->link);
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put_uncharge_info(rg);
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kfree(rg);
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}
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}
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static inline long
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hugetlb_resv_map_add(struct resv_map *map, struct list_head *rg, long from,
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long to, struct hstate *h, struct hugetlb_cgroup *cg,
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long *regions_needed)
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{
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struct file_region *nrg;
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if (!regions_needed) {
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nrg = get_file_region_entry_from_cache(map, from, to);
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record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg);
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list_add(&nrg->link, rg);
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coalesce_file_region(map, nrg);
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} else
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*regions_needed += 1;
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return to - from;
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}
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/*
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* Must be called with resv->lock held.
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*
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* Calling this with regions_needed != NULL will count the number of pages
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* to be added but will not modify the linked list. And regions_needed will
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* indicate the number of file_regions needed in the cache to carry out to add
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* the regions for this range.
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*/
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static long add_reservation_in_range(struct resv_map *resv, long f, long t,
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struct hugetlb_cgroup *h_cg,
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struct hstate *h, long *regions_needed)
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{
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long add = 0;
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struct list_head *head = &resv->regions;
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long last_accounted_offset = f;
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struct file_region *iter, *trg = NULL;
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struct list_head *rg = NULL;
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if (regions_needed)
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*regions_needed = 0;
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/* In this loop, we essentially handle an entry for the range
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* [last_accounted_offset, iter->from), at every iteration, with some
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* bounds checking.
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*/
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list_for_each_entry_safe(iter, trg, head, link) {
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/* Skip irrelevant regions that start before our range. */
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if (iter->from < f) {
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/* If this region ends after the last accounted offset,
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* then we need to update last_accounted_offset.
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*/
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if (iter->to > last_accounted_offset)
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last_accounted_offset = iter->to;
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continue;
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}
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/* When we find a region that starts beyond our range, we've
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* finished.
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*/
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if (iter->from >= t) {
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rg = iter->link.prev;
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break;
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}
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/* Add an entry for last_accounted_offset -> iter->from, and
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* update last_accounted_offset.
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*/
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if (iter->from > last_accounted_offset)
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add += hugetlb_resv_map_add(resv, iter->link.prev,
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last_accounted_offset,
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iter->from, h, h_cg,
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regions_needed);
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last_accounted_offset = iter->to;
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}
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/* Handle the case where our range extends beyond
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* last_accounted_offset.
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*/
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if (!rg)
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rg = head->prev;
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if (last_accounted_offset < t)
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add += hugetlb_resv_map_add(resv, rg, last_accounted_offset,
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t, h, h_cg, regions_needed);
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return add;
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}
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/* Must be called with resv->lock acquired. Will drop lock to allocate entries.
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*/
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static int allocate_file_region_entries(struct resv_map *resv,
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int regions_needed)
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__must_hold(&resv->lock)
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{
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struct list_head allocated_regions;
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int to_allocate = 0, i = 0;
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struct file_region *trg = NULL, *rg = NULL;
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VM_BUG_ON(regions_needed < 0);
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INIT_LIST_HEAD(&allocated_regions);
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/*
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* Check for sufficient descriptors in the cache to accommodate
|
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* the number of in progress add operations plus regions_needed.
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*
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* This is a while loop because when we drop the lock, some other call
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* to region_add or region_del may have consumed some region_entries,
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* so we keep looping here until we finally have enough entries for
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* (adds_in_progress + regions_needed).
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*/
|
|
while (resv->region_cache_count <
|
|
(resv->adds_in_progress + regions_needed)) {
|
|
to_allocate = resv->adds_in_progress + regions_needed -
|
|
resv->region_cache_count;
|
|
|
|
/* At this point, we should have enough entries in the cache
|
|
* for all the existing adds_in_progress. We should only be
|
|
* needing to allocate for regions_needed.
|
|
*/
|
|
VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress);
|
|
|
|
spin_unlock(&resv->lock);
|
|
for (i = 0; i < to_allocate; i++) {
|
|
trg = kmalloc(sizeof(*trg), GFP_KERNEL);
|
|
if (!trg)
|
|
goto out_of_memory;
|
|
list_add(&trg->link, &allocated_regions);
|
|
}
|
|
|
|
spin_lock(&resv->lock);
|
|
|
|
list_splice(&allocated_regions, &resv->region_cache);
|
|
resv->region_cache_count += to_allocate;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_of_memory:
|
|
list_for_each_entry_safe(rg, trg, &allocated_regions, link) {
|
|
list_del(&rg->link);
|
|
kfree(rg);
|
|
}
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/*
|
|
* Add the huge page range represented by [f, t) to the reserve
|
|
* map. Regions will be taken from the cache to fill in this range.
|
|
* Sufficient regions should exist in the cache due to the previous
|
|
* call to region_chg with the same range, but in some cases the cache will not
|
|
* have sufficient entries due to races with other code doing region_add or
|
|
* region_del. The extra needed entries will be allocated.
|
|
*
|
|
* regions_needed is the out value provided by a previous call to region_chg.
|
|
*
|
|
* Return the number of new huge pages added to the map. This number is greater
|
|
* than or equal to zero. If file_region entries needed to be allocated for
|
|
* this operation and we were not able to allocate, it returns -ENOMEM.
|
|
* region_add of regions of length 1 never allocate file_regions and cannot
|
|
* fail; region_chg will always allocate at least 1 entry and a region_add for
|
|
* 1 page will only require at most 1 entry.
|
|
*/
|
|
static long region_add(struct resv_map *resv, long f, long t,
|
|
long in_regions_needed, struct hstate *h,
|
|
struct hugetlb_cgroup *h_cg)
|
|
{
|
|
long add = 0, actual_regions_needed = 0;
|
|
|
|
spin_lock(&resv->lock);
|
|
retry:
|
|
|
|
/* Count how many regions are actually needed to execute this add. */
|
|
add_reservation_in_range(resv, f, t, NULL, NULL,
|
|
&actual_regions_needed);
|
|
|
|
/*
|
|
* Check for sufficient descriptors in the cache to accommodate
|
|
* this add operation. Note that actual_regions_needed may be greater
|
|
* than in_regions_needed, as the resv_map may have been modified since
|
|
* the region_chg call. In this case, we need to make sure that we
|
|
* allocate extra entries, such that we have enough for all the
|
|
* existing adds_in_progress, plus the excess needed for this
|
|
* operation.
|
|
*/
|
|
if (actual_regions_needed > in_regions_needed &&
|
|
resv->region_cache_count <
|
|
resv->adds_in_progress +
|
|
(actual_regions_needed - in_regions_needed)) {
|
|
/* region_add operation of range 1 should never need to
|
|
* allocate file_region entries.
|
|
*/
|
|
VM_BUG_ON(t - f <= 1);
|
|
|
|
if (allocate_file_region_entries(
|
|
resv, actual_regions_needed - in_regions_needed)) {
|
|
return -ENOMEM;
|
|
}
|
|
|
|
goto retry;
|
|
}
|
|
|
|
add = add_reservation_in_range(resv, f, t, h_cg, h, NULL);
|
|
|
|
resv->adds_in_progress -= in_regions_needed;
|
|
|
|
spin_unlock(&resv->lock);
|
|
return add;
|
|
}
|
|
|
|
/*
|
|
* Examine the existing reserve map and determine how many
|
|
* huge pages in the specified range [f, t) are NOT currently
|
|
* represented. This routine is called before a subsequent
|
|
* call to region_add that will actually modify the reserve
|
|
* map to add the specified range [f, t). region_chg does
|
|
* not change the number of huge pages represented by the
|
|
* map. A number of new file_region structures is added to the cache as a
|
|
* placeholder, for the subsequent region_add call to use. At least 1
|
|
* file_region structure is added.
|
|
*
|
|
* out_regions_needed is the number of regions added to the
|
|
* resv->adds_in_progress. This value needs to be provided to a follow up call
|
|
* to region_add or region_abort for proper accounting.
|
|
*
|
|
* Returns the number of huge pages that need to be added to the existing
|
|
* reservation map for the range [f, t). This number is greater or equal to
|
|
* zero. -ENOMEM is returned if a new file_region structure or cache entry
|
|
* is needed and can not be allocated.
|
|
*/
|
|
static long region_chg(struct resv_map *resv, long f, long t,
|
|
long *out_regions_needed)
|
|
{
|
|
long chg = 0;
|
|
|
|
spin_lock(&resv->lock);
|
|
|
|
/* Count how many hugepages in this range are NOT represented. */
|
|
chg = add_reservation_in_range(resv, f, t, NULL, NULL,
|
|
out_regions_needed);
|
|
|
|
if (*out_regions_needed == 0)
|
|
*out_regions_needed = 1;
|
|
|
|
if (allocate_file_region_entries(resv, *out_regions_needed))
|
|
return -ENOMEM;
|
|
|
|
resv->adds_in_progress += *out_regions_needed;
|
|
|
|
spin_unlock(&resv->lock);
|
|
return chg;
|
|
}
|
|
|
|
/*
|
|
* Abort the in progress add operation. The adds_in_progress field
|
|
* of the resv_map keeps track of the operations in progress between
|
|
* calls to region_chg and region_add. Operations are sometimes
|
|
* aborted after the call to region_chg. In such cases, region_abort
|
|
* is called to decrement the adds_in_progress counter. regions_needed
|
|
* is the value returned by the region_chg call, it is used to decrement
|
|
* the adds_in_progress counter.
|
|
*
|
|
* NOTE: The range arguments [f, t) are not needed or used in this
|
|
* routine. They are kept to make reading the calling code easier as
|
|
* arguments will match the associated region_chg call.
|
|
*/
|
|
static void region_abort(struct resv_map *resv, long f, long t,
|
|
long regions_needed)
|
|
{
|
|
spin_lock(&resv->lock);
|
|
VM_BUG_ON(!resv->region_cache_count);
|
|
resv->adds_in_progress -= regions_needed;
|
|
spin_unlock(&resv->lock);
|
|
}
|
|
|
|
/*
|
|
* Delete the specified range [f, t) from the reserve map. If the
|
|
* t parameter is LONG_MAX, this indicates that ALL regions after f
|
|
* should be deleted. Locate the regions which intersect [f, t)
|
|
* and either trim, delete or split the existing regions.
|
|
*
|
|
* Returns the number of huge pages deleted from the reserve map.
|
|
* In the normal case, the return value is zero or more. In the
|
|
* case where a region must be split, a new region descriptor must
|
|
* be allocated. If the allocation fails, -ENOMEM will be returned.
|
|
* NOTE: If the parameter t == LONG_MAX, then we will never split
|
|
* a region and possibly return -ENOMEM. Callers specifying
|
|
* t == LONG_MAX do not need to check for -ENOMEM error.
|
|
*/
|
|
static long region_del(struct resv_map *resv, long f, long t)
|
|
{
|
|
struct list_head *head = &resv->regions;
|
|
struct file_region *rg, *trg;
|
|
struct file_region *nrg = NULL;
|
|
long del = 0;
|
|
|
|
retry:
|
|
spin_lock(&resv->lock);
|
|
list_for_each_entry_safe(rg, trg, head, link) {
|
|
/*
|
|
* Skip regions before the range to be deleted. file_region
|
|
* ranges are normally of the form [from, to). However, there
|
|
* may be a "placeholder" entry in the map which is of the form
|
|
* (from, to) with from == to. Check for placeholder entries
|
|
* at the beginning of the range to be deleted.
|
|
*/
|
|
if (rg->to <= f && (rg->to != rg->from || rg->to != f))
|
|
continue;
|
|
|
|
if (rg->from >= t)
|
|
break;
|
|
|
|
if (f > rg->from && t < rg->to) { /* Must split region */
|
|
/*
|
|
* Check for an entry in the cache before dropping
|
|
* lock and attempting allocation.
|
|
*/
|
|
if (!nrg &&
|
|
resv->region_cache_count > resv->adds_in_progress) {
|
|
nrg = list_first_entry(&resv->region_cache,
|
|
struct file_region,
|
|
link);
|
|
list_del(&nrg->link);
|
|
resv->region_cache_count--;
|
|
}
|
|
|
|
if (!nrg) {
|
|
spin_unlock(&resv->lock);
|
|
nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
|
|
if (!nrg)
|
|
return -ENOMEM;
|
|
goto retry;
|
|
}
|
|
|
|
del += t - f;
|
|
hugetlb_cgroup_uncharge_file_region(
|
|
resv, rg, t - f, false);
|
|
|
|
/* New entry for end of split region */
|
|
nrg->from = t;
|
|
nrg->to = rg->to;
|
|
|
|
copy_hugetlb_cgroup_uncharge_info(nrg, rg);
|
|
|
|
INIT_LIST_HEAD(&nrg->link);
|
|
|
|
/* Original entry is trimmed */
|
|
rg->to = f;
|
|
|
|
list_add(&nrg->link, &rg->link);
|
|
nrg = NULL;
|
|
break;
|
|
}
|
|
|
|
if (f <= rg->from && t >= rg->to) { /* Remove entire region */
|
|
del += rg->to - rg->from;
|
|
hugetlb_cgroup_uncharge_file_region(resv, rg,
|
|
rg->to - rg->from, true);
|
|
list_del(&rg->link);
|
|
kfree(rg);
|
|
continue;
|
|
}
|
|
|
|
if (f <= rg->from) { /* Trim beginning of region */
|
|
hugetlb_cgroup_uncharge_file_region(resv, rg,
|
|
t - rg->from, false);
|
|
|
|
del += t - rg->from;
|
|
rg->from = t;
|
|
} else { /* Trim end of region */
|
|
hugetlb_cgroup_uncharge_file_region(resv, rg,
|
|
rg->to - f, false);
|
|
|
|
del += rg->to - f;
|
|
rg->to = f;
|
|
}
|
|
}
|
|
|
|
spin_unlock(&resv->lock);
|
|
kfree(nrg);
|
|
return del;
|
|
}
|
|
|
|
/*
|
|
* A rare out of memory error was encountered which prevented removal of
|
|
* the reserve map region for a page. The huge page itself was free'ed
|
|
* and removed from the page cache. This routine will adjust the subpool
|
|
* usage count, and the global reserve count if needed. By incrementing
|
|
* these counts, the reserve map entry which could not be deleted will
|
|
* appear as a "reserved" entry instead of simply dangling with incorrect
|
|
* counts.
|
|
*/
|
|
void hugetlb_fix_reserve_counts(struct inode *inode)
|
|
{
|
|
struct hugepage_subpool *spool = subpool_inode(inode);
|
|
long rsv_adjust;
|
|
bool reserved = false;
|
|
|
|
rsv_adjust = hugepage_subpool_get_pages(spool, 1);
|
|
if (rsv_adjust > 0) {
|
|
struct hstate *h = hstate_inode(inode);
|
|
|
|
if (!hugetlb_acct_memory(h, 1))
|
|
reserved = true;
|
|
} else if (!rsv_adjust) {
|
|
reserved = true;
|
|
}
|
|
|
|
if (!reserved)
|
|
pr_warn("hugetlb: Huge Page Reserved count may go negative.\n");
|
|
}
|
|
|
|
/*
|
|
* Count and return the number of huge pages in the reserve map
|
|
* that intersect with the range [f, t).
|
|
*/
|
|
static long region_count(struct resv_map *resv, long f, long t)
|
|
{
|
|
struct list_head *head = &resv->regions;
|
|
struct file_region *rg;
|
|
long chg = 0;
|
|
|
|
spin_lock(&resv->lock);
|
|
/* Locate each segment we overlap with, and count that overlap. */
|
|
list_for_each_entry(rg, head, link) {
|
|
long seg_from;
|
|
long seg_to;
|
|
|
|
if (rg->to <= f)
|
|
continue;
|
|
if (rg->from >= t)
|
|
break;
|
|
|
|
seg_from = max(rg->from, f);
|
|
seg_to = min(rg->to, t);
|
|
|
|
chg += seg_to - seg_from;
|
|
}
|
|
spin_unlock(&resv->lock);
|
|
|
|
return chg;
|
|
}
|
|
|
|
/*
|
|
* Convert the address within this vma to the page offset within
|
|
* the mapping, in pagecache page units; huge pages here.
|
|
*/
|
|
static pgoff_t vma_hugecache_offset(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long address)
|
|
{
|
|
return ((address - vma->vm_start) >> huge_page_shift(h)) +
|
|
(vma->vm_pgoff >> huge_page_order(h));
|
|
}
|
|
|
|
pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
|
|
unsigned long address)
|
|
{
|
|
return vma_hugecache_offset(hstate_vma(vma), vma, address);
|
|
}
|
|
EXPORT_SYMBOL_GPL(linear_hugepage_index);
|
|
|
|
/*
|
|
* Return the size of the pages allocated when backing a VMA. In the majority
|
|
* cases this will be same size as used by the page table entries.
|
|
*/
|
|
unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
|
|
{
|
|
if (vma->vm_ops && vma->vm_ops->pagesize)
|
|
return vma->vm_ops->pagesize(vma);
|
|
return PAGE_SIZE;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vma_kernel_pagesize);
|
|
|
|
/*
|
|
* Return the page size being used by the MMU to back a VMA. In the majority
|
|
* of cases, the page size used by the kernel matches the MMU size. On
|
|
* architectures where it differs, an architecture-specific 'strong'
|
|
* version of this symbol is required.
|
|
*/
|
|
__weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
|
|
{
|
|
return vma_kernel_pagesize(vma);
|
|
}
|
|
|
|
/*
|
|
* Flags for MAP_PRIVATE reservations. These are stored in the bottom
|
|
* bits of the reservation map pointer, which are always clear due to
|
|
* alignment.
|
|
*/
|
|
#define HPAGE_RESV_OWNER (1UL << 0)
|
|
#define HPAGE_RESV_UNMAPPED (1UL << 1)
|
|
#define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
|
|
|
|
/*
|
|
* These helpers are used to track how many pages are reserved for
|
|
* faults in a MAP_PRIVATE mapping. Only the process that called mmap()
|
|
* is guaranteed to have their future faults succeed.
|
|
*
|
|
* With the exception of reset_vma_resv_huge_pages() which is called at fork(),
|
|
* the reserve counters are updated with the hugetlb_lock held. It is safe
|
|
* to reset the VMA at fork() time as it is not in use yet and there is no
|
|
* chance of the global counters getting corrupted as a result of the values.
|
|
*
|
|
* The private mapping reservation is represented in a subtly different
|
|
* manner to a shared mapping. A shared mapping has a region map associated
|
|
* with the underlying file, this region map represents the backing file
|
|
* pages which have ever had a reservation assigned which this persists even
|
|
* after the page is instantiated. A private mapping has a region map
|
|
* associated with the original mmap which is attached to all VMAs which
|
|
* reference it, this region map represents those offsets which have consumed
|
|
* reservation ie. where pages have been instantiated.
|
|
*/
|
|
static unsigned long get_vma_private_data(struct vm_area_struct *vma)
|
|
{
|
|
return (unsigned long)vma->vm_private_data;
|
|
}
|
|
|
|
static void set_vma_private_data(struct vm_area_struct *vma,
|
|
unsigned long value)
|
|
{
|
|
vma->vm_private_data = (void *)value;
|
|
}
|
|
|
|
static void
|
|
resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map,
|
|
struct hugetlb_cgroup *h_cg,
|
|
struct hstate *h)
|
|
{
|
|
#ifdef CONFIG_CGROUP_HUGETLB
|
|
if (!h_cg || !h) {
|
|
resv_map->reservation_counter = NULL;
|
|
resv_map->pages_per_hpage = 0;
|
|
resv_map->css = NULL;
|
|
} else {
|
|
resv_map->reservation_counter =
|
|
&h_cg->rsvd_hugepage[hstate_index(h)];
|
|
resv_map->pages_per_hpage = pages_per_huge_page(h);
|
|
resv_map->css = &h_cg->css;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
struct resv_map *resv_map_alloc(void)
|
|
{
|
|
struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
|
|
struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL);
|
|
|
|
if (!resv_map || !rg) {
|
|
kfree(resv_map);
|
|
kfree(rg);
|
|
return NULL;
|
|
}
|
|
|
|
kref_init(&resv_map->refs);
|
|
spin_lock_init(&resv_map->lock);
|
|
INIT_LIST_HEAD(&resv_map->regions);
|
|
|
|
resv_map->adds_in_progress = 0;
|
|
/*
|
|
* Initialize these to 0. On shared mappings, 0's here indicate these
|
|
* fields don't do cgroup accounting. On private mappings, these will be
|
|
* re-initialized to the proper values, to indicate that hugetlb cgroup
|
|
* reservations are to be un-charged from here.
|
|
*/
|
|
resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL);
|
|
|
|
INIT_LIST_HEAD(&resv_map->region_cache);
|
|
list_add(&rg->link, &resv_map->region_cache);
|
|
resv_map->region_cache_count = 1;
|
|
|
|
return resv_map;
|
|
}
|
|
|
|
void resv_map_release(struct kref *ref)
|
|
{
|
|
struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
|
|
struct list_head *head = &resv_map->region_cache;
|
|
struct file_region *rg, *trg;
|
|
|
|
/* Clear out any active regions before we release the map. */
|
|
region_del(resv_map, 0, LONG_MAX);
|
|
|
|
/* ... and any entries left in the cache */
|
|
list_for_each_entry_safe(rg, trg, head, link) {
|
|
list_del(&rg->link);
|
|
kfree(rg);
|
|
}
|
|
|
|
VM_BUG_ON(resv_map->adds_in_progress);
|
|
|
|
kfree(resv_map);
|
|
}
|
|
|
|
static inline struct resv_map *inode_resv_map(struct inode *inode)
|
|
{
|
|
/*
|
|
* At inode evict time, i_mapping may not point to the original
|
|
* address space within the inode. This original address space
|
|
* contains the pointer to the resv_map. So, always use the
|
|
* address space embedded within the inode.
|
|
* The VERY common case is inode->mapping == &inode->i_data but,
|
|
* this may not be true for device special inodes.
|
|
*/
|
|
return (struct resv_map *)(&inode->i_data)->private_data;
|
|
}
|
|
|
|
static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
|
|
{
|
|
VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
|
|
if (vma->vm_flags & VM_MAYSHARE) {
|
|
struct address_space *mapping = vma->vm_file->f_mapping;
|
|
struct inode *inode = mapping->host;
|
|
|
|
return inode_resv_map(inode);
|
|
|
|
} else {
|
|
return (struct resv_map *)(get_vma_private_data(vma) &
|
|
~HPAGE_RESV_MASK);
|
|
}
|
|
}
|
|
|
|
static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
|
|
{
|
|
VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
|
|
VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma);
|
|
|
|
set_vma_private_data(vma, (get_vma_private_data(vma) &
|
|
HPAGE_RESV_MASK) | (unsigned long)map);
|
|
}
|
|
|
|
static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
|
|
{
|
|
VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
|
|
VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma);
|
|
|
|
set_vma_private_data(vma, get_vma_private_data(vma) | flags);
|
|
}
|
|
|
|
static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag)
|
|
{
|
|
VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
|
|
|
|
return (get_vma_private_data(vma) & flag) != 0;
|
|
}
|
|
|
|
/* Reset counters to 0 and clear all HPAGE_RESV_* flags */
|
|
void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
|
|
{
|
|
VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
|
|
if (!(vma->vm_flags & VM_MAYSHARE))
|
|
vma->vm_private_data = (void *)0;
|
|
}
|
|
|
|
/*
|
|
* Reset and decrement one ref on hugepage private reservation.
|
|
* Called with mm->mmap_sem writer semaphore held.
|
|
* This function should be only used by move_vma() and operate on
|
|
* same sized vma. It should never come here with last ref on the
|
|
* reservation.
|
|
*/
|
|
void clear_vma_resv_huge_pages(struct vm_area_struct *vma)
|
|
{
|
|
/*
|
|
* Clear the old hugetlb private page reservation.
|
|
* It has already been transferred to new_vma.
|
|
*
|
|
* During a mremap() operation of a hugetlb vma we call move_vma()
|
|
* which copies vma into new_vma and unmaps vma. After the copy
|
|
* operation both new_vma and vma share a reference to the resv_map
|
|
* struct, and at that point vma is about to be unmapped. We don't
|
|
* want to return the reservation to the pool at unmap of vma because
|
|
* the reservation still lives on in new_vma, so simply decrement the
|
|
* ref here and remove the resv_map reference from this vma.
|
|
*/
|
|
struct resv_map *reservations = vma_resv_map(vma);
|
|
|
|
if (reservations && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
|
|
resv_map_put_hugetlb_cgroup_uncharge_info(reservations);
|
|
kref_put(&reservations->refs, resv_map_release);
|
|
}
|
|
|
|
reset_vma_resv_huge_pages(vma);
|
|
}
|
|
|
|
/* Returns true if the VMA has associated reserve pages */
|
|
static bool vma_has_reserves(struct vm_area_struct *vma, long chg)
|
|
{
|
|
if (vma->vm_flags & VM_NORESERVE) {
|
|
/*
|
|
* This address is already reserved by other process(chg == 0),
|
|
* so, we should decrement reserved count. Without decrementing,
|
|
* reserve count remains after releasing inode, because this
|
|
* allocated page will go into page cache and is regarded as
|
|
* coming from reserved pool in releasing step. Currently, we
|
|
* don't have any other solution to deal with this situation
|
|
* properly, so add work-around here.
|
|
*/
|
|
if (vma->vm_flags & VM_MAYSHARE && chg == 0)
|
|
return true;
|
|
else
|
|
return false;
|
|
}
|
|
|
|
/* Shared mappings always use reserves */
|
|
if (vma->vm_flags & VM_MAYSHARE) {
|
|
/*
|
|
* We know VM_NORESERVE is not set. Therefore, there SHOULD
|
|
* be a region map for all pages. The only situation where
|
|
* there is no region map is if a hole was punched via
|
|
* fallocate. In this case, there really are no reserves to
|
|
* use. This situation is indicated if chg != 0.
|
|
*/
|
|
if (chg)
|
|
return false;
|
|
else
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Only the process that called mmap() has reserves for
|
|
* private mappings.
|
|
*/
|
|
if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
|
|
/*
|
|
* Like the shared case above, a hole punch or truncate
|
|
* could have been performed on the private mapping.
|
|
* Examine the value of chg to determine if reserves
|
|
* actually exist or were previously consumed.
|
|
* Very Subtle - The value of chg comes from a previous
|
|
* call to vma_needs_reserves(). The reserve map for
|
|
* private mappings has different (opposite) semantics
|
|
* than that of shared mappings. vma_needs_reserves()
|
|
* has already taken this difference in semantics into
|
|
* account. Therefore, the meaning of chg is the same
|
|
* as in the shared case above. Code could easily be
|
|
* combined, but keeping it separate draws attention to
|
|
* subtle differences.
|
|
*/
|
|
if (chg)
|
|
return false;
|
|
else
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static void enqueue_huge_page(struct hstate *h, struct page *page)
|
|
{
|
|
int nid = page_to_nid(page);
|
|
|
|
lockdep_assert_held(&hugetlb_lock);
|
|
VM_BUG_ON_PAGE(page_count(page), page);
|
|
|
|
list_move(&page->lru, &h->hugepage_freelists[nid]);
|
|
h->free_huge_pages++;
|
|
h->free_huge_pages_node[nid]++;
|
|
SetHPageFreed(page);
|
|
}
|
|
|
|
static struct page *dequeue_huge_page_node_exact(struct hstate *h, int nid)
|
|
{
|
|
struct page *page;
|
|
bool pin = !!(current->flags & PF_MEMALLOC_PIN);
|
|
|
|
lockdep_assert_held(&hugetlb_lock);
|
|
list_for_each_entry(page, &h->hugepage_freelists[nid], lru) {
|
|
if (pin && !is_pinnable_page(page))
|
|
continue;
|
|
|
|
if (PageHWPoison(page))
|
|
continue;
|
|
|
|
list_move(&page->lru, &h->hugepage_activelist);
|
|
set_page_refcounted(page);
|
|
ClearHPageFreed(page);
|
|
h->free_huge_pages--;
|
|
h->free_huge_pages_node[nid]--;
|
|
return page;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct page *dequeue_huge_page_nodemask(struct hstate *h, gfp_t gfp_mask, int nid,
|
|
nodemask_t *nmask)
|
|
{
|
|
unsigned int cpuset_mems_cookie;
|
|
struct zonelist *zonelist;
|
|
struct zone *zone;
|
|
struct zoneref *z;
|
|
int node = NUMA_NO_NODE;
|
|
|
|
zonelist = node_zonelist(nid, gfp_mask);
|
|
|
|
retry_cpuset:
|
|
cpuset_mems_cookie = read_mems_allowed_begin();
|
|
for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) {
|
|
struct page *page;
|
|
|
|
if (!cpuset_zone_allowed(zone, gfp_mask))
|
|
continue;
|
|
/*
|
|
* no need to ask again on the same node. Pool is node rather than
|
|
* zone aware
|
|
*/
|
|
if (zone_to_nid(zone) == node)
|
|
continue;
|
|
node = zone_to_nid(zone);
|
|
|
|
page = dequeue_huge_page_node_exact(h, node);
|
|
if (page)
|
|
return page;
|
|
}
|
|
if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie)))
|
|
goto retry_cpuset;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct page *dequeue_huge_page_vma(struct hstate *h,
|
|
struct vm_area_struct *vma,
|
|
unsigned long address, int avoid_reserve,
|
|
long chg)
|
|
{
|
|
struct page *page = NULL;
|
|
struct mempolicy *mpol;
|
|
gfp_t gfp_mask;
|
|
nodemask_t *nodemask;
|
|
int nid;
|
|
|
|
/*
|
|
* A child process with MAP_PRIVATE mappings created by their parent
|
|
* have no page reserves. This check ensures that reservations are
|
|
* not "stolen". The child may still get SIGKILLed
|
|
*/
|
|
if (!vma_has_reserves(vma, chg) &&
|
|
h->free_huge_pages - h->resv_huge_pages == 0)
|
|
goto err;
|
|
|
|
/* If reserves cannot be used, ensure enough pages are in the pool */
|
|
if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
|
|
goto err;
|
|
|
|
gfp_mask = htlb_alloc_mask(h);
|
|
nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
|
|
|
|
if (mpol_is_preferred_many(mpol)) {
|
|
page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask);
|
|
|
|
/* Fallback to all nodes if page==NULL */
|
|
nodemask = NULL;
|
|
}
|
|
|
|
if (!page)
|
|
page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask);
|
|
|
|
if (page && !avoid_reserve && vma_has_reserves(vma, chg)) {
|
|
SetHPageRestoreReserve(page);
|
|
h->resv_huge_pages--;
|
|
}
|
|
|
|
mpol_cond_put(mpol);
|
|
return page;
|
|
|
|
err:
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* common helper functions for hstate_next_node_to_{alloc|free}.
|
|
* We may have allocated or freed a huge page based on a different
|
|
* nodes_allowed previously, so h->next_node_to_{alloc|free} might
|
|
* be outside of *nodes_allowed. Ensure that we use an allowed
|
|
* node for alloc or free.
|
|
*/
|
|
static int next_node_allowed(int nid, nodemask_t *nodes_allowed)
|
|
{
|
|
nid = next_node_in(nid, *nodes_allowed);
|
|
VM_BUG_ON(nid >= MAX_NUMNODES);
|
|
|
|
return nid;
|
|
}
|
|
|
|
static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed)
|
|
{
|
|
if (!node_isset(nid, *nodes_allowed))
|
|
nid = next_node_allowed(nid, nodes_allowed);
|
|
return nid;
|
|
}
|
|
|
|
/*
|
|
* returns the previously saved node ["this node"] from which to
|
|
* allocate a persistent huge page for the pool and advance the
|
|
* next node from which to allocate, handling wrap at end of node
|
|
* mask.
|
|
*/
|
|
static int hstate_next_node_to_alloc(struct hstate *h,
|
|
nodemask_t *nodes_allowed)
|
|
{
|
|
int nid;
|
|
|
|
VM_BUG_ON(!nodes_allowed);
|
|
|
|
nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed);
|
|
h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed);
|
|
|
|
return nid;
|
|
}
|
|
|
|
/*
|
|
* helper for remove_pool_huge_page() - return the previously saved
|
|
* node ["this node"] from which to free a huge page. Advance the
|
|
* next node id whether or not we find a free huge page to free so
|
|
* that the next attempt to free addresses the next node.
|
|
*/
|
|
static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
|
|
{
|
|
int nid;
|
|
|
|
VM_BUG_ON(!nodes_allowed);
|
|
|
|
nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed);
|
|
h->next_nid_to_free = next_node_allowed(nid, nodes_allowed);
|
|
|
|
return nid;
|
|
}
|
|
|
|
#define for_each_node_mask_to_alloc(hs, nr_nodes, node, mask) \
|
|
for (nr_nodes = nodes_weight(*mask); \
|
|
nr_nodes > 0 && \
|
|
((node = hstate_next_node_to_alloc(hs, mask)) || 1); \
|
|
nr_nodes--)
|
|
|
|
#define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \
|
|
for (nr_nodes = nodes_weight(*mask); \
|
|
nr_nodes > 0 && \
|
|
((node = hstate_next_node_to_free(hs, mask)) || 1); \
|
|
nr_nodes--)
|
|
|
|
/* used to demote non-gigantic_huge pages as well */
|
|
static void __destroy_compound_gigantic_page(struct page *page,
|
|
unsigned int order, bool demote)
|
|
{
|
|
int i;
|
|
int nr_pages = 1 << order;
|
|
struct page *p = page + 1;
|
|
|
|
atomic_set(compound_mapcount_ptr(page), 0);
|
|
atomic_set(compound_pincount_ptr(page), 0);
|
|
|
|
for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
|
|
p->mapping = NULL;
|
|
clear_compound_head(p);
|
|
if (!demote)
|
|
set_page_refcounted(p);
|
|
}
|
|
|
|
set_compound_order(page, 0);
|
|
#ifdef CONFIG_64BIT
|
|
page[1].compound_nr = 0;
|
|
#endif
|
|
__ClearPageHead(page);
|
|
}
|
|
|
|
static void destroy_compound_hugetlb_page_for_demote(struct page *page,
|
|
unsigned int order)
|
|
{
|
|
__destroy_compound_gigantic_page(page, order, true);
|
|
}
|
|
|
|
#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE
|
|
static void destroy_compound_gigantic_page(struct page *page,
|
|
unsigned int order)
|
|
{
|
|
__destroy_compound_gigantic_page(page, order, false);
|
|
}
|
|
|
|
static void free_gigantic_page(struct page *page, unsigned int order)
|
|
{
|
|
/*
|
|
* If the page isn't allocated using the cma allocator,
|
|
* cma_release() returns false.
|
|
*/
|
|
#ifdef CONFIG_CMA
|
|
if (cma_release(hugetlb_cma[page_to_nid(page)], page, 1 << order))
|
|
return;
|
|
#endif
|
|
|
|
free_contig_range(page_to_pfn(page), 1 << order);
|
|
}
|
|
|
|
#ifdef CONFIG_CONTIG_ALLOC
|
|
static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
|
|
int nid, nodemask_t *nodemask)
|
|
{
|
|
unsigned long nr_pages = pages_per_huge_page(h);
|
|
if (nid == NUMA_NO_NODE)
|
|
nid = numa_mem_id();
|
|
|
|
#ifdef CONFIG_CMA
|
|
{
|
|
struct page *page;
|
|
int node;
|
|
|
|
if (hugetlb_cma[nid]) {
|
|
page = cma_alloc(hugetlb_cma[nid], nr_pages,
|
|
huge_page_order(h), true);
|
|
if (page)
|
|
return page;
|
|
}
|
|
|
|
if (!(gfp_mask & __GFP_THISNODE)) {
|
|
for_each_node_mask(node, *nodemask) {
|
|
if (node == nid || !hugetlb_cma[node])
|
|
continue;
|
|
|
|
page = cma_alloc(hugetlb_cma[node], nr_pages,
|
|
huge_page_order(h), true);
|
|
if (page)
|
|
return page;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
return alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask);
|
|
}
|
|
|
|
#else /* !CONFIG_CONTIG_ALLOC */
|
|
static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
|
|
int nid, nodemask_t *nodemask)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif /* CONFIG_CONTIG_ALLOC */
|
|
|
|
#else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */
|
|
static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
|
|
int nid, nodemask_t *nodemask)
|
|
{
|
|
return NULL;
|
|
}
|
|
static inline void free_gigantic_page(struct page *page, unsigned int order) { }
|
|
static inline void destroy_compound_gigantic_page(struct page *page,
|
|
unsigned int order) { }
|
|
#endif
|
|
|
|
/*
|
|
* Remove hugetlb page from lists, and update dtor so that page appears
|
|
* as just a compound page.
|
|
*
|
|
* A reference is held on the page, except in the case of demote.
|
|
*
|
|
* Must be called with hugetlb lock held.
|
|
*/
|
|
static void __remove_hugetlb_page(struct hstate *h, struct page *page,
|
|
bool adjust_surplus,
|
|
bool demote)
|
|
{
|
|
int nid = page_to_nid(page);
|
|
|
|
VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page);
|
|
VM_BUG_ON_PAGE(hugetlb_cgroup_from_page_rsvd(page), page);
|
|
|
|
lockdep_assert_held(&hugetlb_lock);
|
|
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
|
|
return;
|
|
|
|
list_del(&page->lru);
|
|
|
|
if (HPageFreed(page)) {
|
|
h->free_huge_pages--;
|
|
h->free_huge_pages_node[nid]--;
|
|
}
|
|
if (adjust_surplus) {
|
|
h->surplus_huge_pages--;
|
|
h->surplus_huge_pages_node[nid]--;
|
|
}
|
|
|
|
/*
|
|
* Very subtle
|
|
*
|
|
* For non-gigantic pages set the destructor to the normal compound
|
|
* page dtor. This is needed in case someone takes an additional
|
|
* temporary ref to the page, and freeing is delayed until they drop
|
|
* their reference.
|
|
*
|
|
* For gigantic pages set the destructor to the null dtor. This
|
|
* destructor will never be called. Before freeing the gigantic
|
|
* page destroy_compound_gigantic_page will turn the compound page
|
|
* into a simple group of pages. After this the destructor does not
|
|
* apply.
|
|
*
|
|
* This handles the case where more than one ref is held when and
|
|
* after update_and_free_page is called.
|
|
*
|
|
* In the case of demote we do not ref count the page as it will soon
|
|
* be turned into a page of smaller size.
|
|
*/
|
|
if (!demote)
|
|
set_page_refcounted(page);
|
|
if (hstate_is_gigantic(h))
|
|
set_compound_page_dtor(page, NULL_COMPOUND_DTOR);
|
|
else
|
|
set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
|
|
|
|
h->nr_huge_pages--;
|
|
h->nr_huge_pages_node[nid]--;
|
|
}
|
|
|
|
static void remove_hugetlb_page(struct hstate *h, struct page *page,
|
|
bool adjust_surplus)
|
|
{
|
|
__remove_hugetlb_page(h, page, adjust_surplus, false);
|
|
}
|
|
|
|
static void remove_hugetlb_page_for_demote(struct hstate *h, struct page *page,
|
|
bool adjust_surplus)
|
|
{
|
|
__remove_hugetlb_page(h, page, adjust_surplus, true);
|
|
}
|
|
|
|
static void add_hugetlb_page(struct hstate *h, struct page *page,
|
|
bool adjust_surplus)
|
|
{
|
|
int zeroed;
|
|
int nid = page_to_nid(page);
|
|
|
|
VM_BUG_ON_PAGE(!HPageVmemmapOptimized(page), page);
|
|
|
|
lockdep_assert_held(&hugetlb_lock);
|
|
|
|
INIT_LIST_HEAD(&page->lru);
|
|
h->nr_huge_pages++;
|
|
h->nr_huge_pages_node[nid]++;
|
|
|
|
if (adjust_surplus) {
|
|
h->surplus_huge_pages++;
|
|
h->surplus_huge_pages_node[nid]++;
|
|
}
|
|
|
|
set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);
|
|
set_page_private(page, 0);
|
|
SetHPageVmemmapOptimized(page);
|
|
|
|
/*
|
|
* This page is about to be managed by the hugetlb allocator and
|
|
* should have no users. Drop our reference, and check for others
|
|
* just in case.
|
|
*/
|
|
zeroed = put_page_testzero(page);
|
|
if (!zeroed)
|
|
/*
|
|
* It is VERY unlikely soneone else has taken a ref on
|
|
* the page. In this case, we simply return as the
|
|
* hugetlb destructor (free_huge_page) will be called
|
|
* when this other ref is dropped.
|
|
*/
|
|
return;
|
|
|
|
arch_clear_hugepage_flags(page);
|
|
enqueue_huge_page(h, page);
|
|
}
|
|
|
|
static void __update_and_free_page(struct hstate *h, struct page *page)
|
|
{
|
|
int i;
|
|
struct page *subpage = page;
|
|
|
|
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
|
|
return;
|
|
|
|
if (hugetlb_vmemmap_alloc(h, page)) {
|
|
spin_lock_irq(&hugetlb_lock);
|
|
/*
|
|
* If we cannot allocate vmemmap pages, just refuse to free the
|
|
* page and put the page back on the hugetlb free list and treat
|
|
* as a surplus page.
|
|
*/
|
|
add_hugetlb_page(h, page, true);
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
return;
|
|
}
|
|
|
|
for (i = 0; i < pages_per_huge_page(h);
|
|
i++, subpage = mem_map_next(subpage, page, i)) {
|
|
subpage->flags &= ~(1 << PG_locked | 1 << PG_error |
|
|
1 << PG_referenced | 1 << PG_dirty |
|
|
1 << PG_active | 1 << PG_private |
|
|
1 << PG_writeback);
|
|
}
|
|
|
|
/*
|
|
* Non-gigantic pages demoted from CMA allocated gigantic pages
|
|
* need to be given back to CMA in free_gigantic_page.
|
|
*/
|
|
if (hstate_is_gigantic(h) ||
|
|
hugetlb_cma_page(page, huge_page_order(h))) {
|
|
destroy_compound_gigantic_page(page, huge_page_order(h));
|
|
free_gigantic_page(page, huge_page_order(h));
|
|
} else {
|
|
__free_pages(page, huge_page_order(h));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* As update_and_free_page() can be called under any context, so we cannot
|
|
* use GFP_KERNEL to allocate vmemmap pages. However, we can defer the
|
|
* actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate
|
|
* the vmemmap pages.
|
|
*
|
|
* free_hpage_workfn() locklessly retrieves the linked list of pages to be
|
|
* freed and frees them one-by-one. As the page->mapping pointer is going
|
|
* to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node
|
|
* structure of a lockless linked list of huge pages to be freed.
|
|
*/
|
|
static LLIST_HEAD(hpage_freelist);
|
|
|
|
static void free_hpage_workfn(struct work_struct *work)
|
|
{
|
|
struct llist_node *node;
|
|
|
|
node = llist_del_all(&hpage_freelist);
|
|
|
|
while (node) {
|
|
struct page *page;
|
|
struct hstate *h;
|
|
|
|
page = container_of((struct address_space **)node,
|
|
struct page, mapping);
|
|
node = node->next;
|
|
page->mapping = NULL;
|
|
/*
|
|
* The VM_BUG_ON_PAGE(!PageHuge(page), page) in page_hstate()
|
|
* is going to trigger because a previous call to
|
|
* remove_hugetlb_page() will set_compound_page_dtor(page,
|
|
* NULL_COMPOUND_DTOR), so do not use page_hstate() directly.
|
|
*/
|
|
h = size_to_hstate(page_size(page));
|
|
|
|
__update_and_free_page(h, page);
|
|
|
|
cond_resched();
|
|
}
|
|
}
|
|
static DECLARE_WORK(free_hpage_work, free_hpage_workfn);
|
|
|
|
static inline void flush_free_hpage_work(struct hstate *h)
|
|
{
|
|
if (hugetlb_optimize_vmemmap_pages(h))
|
|
flush_work(&free_hpage_work);
|
|
}
|
|
|
|
static void update_and_free_page(struct hstate *h, struct page *page,
|
|
bool atomic)
|
|
{
|
|
if (!HPageVmemmapOptimized(page) || !atomic) {
|
|
__update_and_free_page(h, page);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages.
|
|
*
|
|
* Only call schedule_work() if hpage_freelist is previously
|
|
* empty. Otherwise, schedule_work() had been called but the workfn
|
|
* hasn't retrieved the list yet.
|
|
*/
|
|
if (llist_add((struct llist_node *)&page->mapping, &hpage_freelist))
|
|
schedule_work(&free_hpage_work);
|
|
}
|
|
|
|
static void update_and_free_pages_bulk(struct hstate *h, struct list_head *list)
|
|
{
|
|
struct page *page, *t_page;
|
|
|
|
list_for_each_entry_safe(page, t_page, list, lru) {
|
|
update_and_free_page(h, page, false);
|
|
cond_resched();
|
|
}
|
|
}
|
|
|
|
struct hstate *size_to_hstate(unsigned long size)
|
|
{
|
|
struct hstate *h;
|
|
|
|
for_each_hstate(h) {
|
|
if (huge_page_size(h) == size)
|
|
return h;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
void free_huge_page(struct page *page)
|
|
{
|
|
/*
|
|
* Can't pass hstate in here because it is called from the
|
|
* compound page destructor.
|
|
*/
|
|
struct hstate *h = page_hstate(page);
|
|
int nid = page_to_nid(page);
|
|
struct hugepage_subpool *spool = hugetlb_page_subpool(page);
|
|
bool restore_reserve;
|
|
unsigned long flags;
|
|
|
|
VM_BUG_ON_PAGE(page_count(page), page);
|
|
VM_BUG_ON_PAGE(page_mapcount(page), page);
|
|
|
|
hugetlb_set_page_subpool(page, NULL);
|
|
if (PageAnon(page))
|
|
__ClearPageAnonExclusive(page);
|
|
page->mapping = NULL;
|
|
restore_reserve = HPageRestoreReserve(page);
|
|
ClearHPageRestoreReserve(page);
|
|
|
|
/*
|
|
* If HPageRestoreReserve was set on page, page allocation consumed a
|
|
* reservation. If the page was associated with a subpool, there
|
|
* would have been a page reserved in the subpool before allocation
|
|
* via hugepage_subpool_get_pages(). Since we are 'restoring' the
|
|
* reservation, do not call hugepage_subpool_put_pages() as this will
|
|
* remove the reserved page from the subpool.
|
|
*/
|
|
if (!restore_reserve) {
|
|
/*
|
|
* A return code of zero implies that the subpool will be
|
|
* under its minimum size if the reservation is not restored
|
|
* after page is free. Therefore, force restore_reserve
|
|
* operation.
|
|
*/
|
|
if (hugepage_subpool_put_pages(spool, 1) == 0)
|
|
restore_reserve = true;
|
|
}
|
|
|
|
spin_lock_irqsave(&hugetlb_lock, flags);
|
|
ClearHPageMigratable(page);
|
|
hugetlb_cgroup_uncharge_page(hstate_index(h),
|
|
pages_per_huge_page(h), page);
|
|
hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h),
|
|
pages_per_huge_page(h), page);
|
|
if (restore_reserve)
|
|
h->resv_huge_pages++;
|
|
|
|
if (HPageTemporary(page)) {
|
|
remove_hugetlb_page(h, page, false);
|
|
spin_unlock_irqrestore(&hugetlb_lock, flags);
|
|
update_and_free_page(h, page, true);
|
|
} else if (h->surplus_huge_pages_node[nid]) {
|
|
/* remove the page from active list */
|
|
remove_hugetlb_page(h, page, true);
|
|
spin_unlock_irqrestore(&hugetlb_lock, flags);
|
|
update_and_free_page(h, page, true);
|
|
} else {
|
|
arch_clear_hugepage_flags(page);
|
|
enqueue_huge_page(h, page);
|
|
spin_unlock_irqrestore(&hugetlb_lock, flags);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Must be called with the hugetlb lock held
|
|
*/
|
|
static void __prep_account_new_huge_page(struct hstate *h, int nid)
|
|
{
|
|
lockdep_assert_held(&hugetlb_lock);
|
|
h->nr_huge_pages++;
|
|
h->nr_huge_pages_node[nid]++;
|
|
}
|
|
|
|
static void __prep_new_huge_page(struct hstate *h, struct page *page)
|
|
{
|
|
hugetlb_vmemmap_free(h, page);
|
|
INIT_LIST_HEAD(&page->lru);
|
|
set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);
|
|
hugetlb_set_page_subpool(page, NULL);
|
|
set_hugetlb_cgroup(page, NULL);
|
|
set_hugetlb_cgroup_rsvd(page, NULL);
|
|
}
|
|
|
|
static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
|
|
{
|
|
__prep_new_huge_page(h, page);
|
|
spin_lock_irq(&hugetlb_lock);
|
|
__prep_account_new_huge_page(h, nid);
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
}
|
|
|
|
static bool __prep_compound_gigantic_page(struct page *page, unsigned int order,
|
|
bool demote)
|
|
{
|
|
int i, j;
|
|
int nr_pages = 1 << order;
|
|
struct page *p = page + 1;
|
|
|
|
/* we rely on prep_new_huge_page to set the destructor */
|
|
set_compound_order(page, order);
|
|
__ClearPageReserved(page);
|
|
__SetPageHead(page);
|
|
for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
|
|
/*
|
|
* For gigantic hugepages allocated through bootmem at
|
|
* boot, it's safer to be consistent with the not-gigantic
|
|
* hugepages and clear the PG_reserved bit from all tail pages
|
|
* too. Otherwise drivers using get_user_pages() to access tail
|
|
* pages may get the reference counting wrong if they see
|
|
* PG_reserved set on a tail page (despite the head page not
|
|
* having PG_reserved set). Enforcing this consistency between
|
|
* head and tail pages allows drivers to optimize away a check
|
|
* on the head page when they need know if put_page() is needed
|
|
* after get_user_pages().
|
|
*/
|
|
__ClearPageReserved(p);
|
|
/*
|
|
* Subtle and very unlikely
|
|
*
|
|
* Gigantic 'page allocators' such as memblock or cma will
|
|
* return a set of pages with each page ref counted. We need
|
|
* to turn this set of pages into a compound page with tail
|
|
* page ref counts set to zero. Code such as speculative page
|
|
* cache adding could take a ref on a 'to be' tail page.
|
|
* We need to respect any increased ref count, and only set
|
|
* the ref count to zero if count is currently 1. If count
|
|
* is not 1, we return an error. An error return indicates
|
|
* the set of pages can not be converted to a gigantic page.
|
|
* The caller who allocated the pages should then discard the
|
|
* pages using the appropriate free interface.
|
|
*
|
|
* In the case of demote, the ref count will be zero.
|
|
*/
|
|
if (!demote) {
|
|
if (!page_ref_freeze(p, 1)) {
|
|
pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n");
|
|
goto out_error;
|
|
}
|
|
} else {
|
|
VM_BUG_ON_PAGE(page_count(p), p);
|
|
}
|
|
set_compound_head(p, page);
|
|
}
|
|
atomic_set(compound_mapcount_ptr(page), -1);
|
|
atomic_set(compound_pincount_ptr(page), 0);
|
|
return true;
|
|
|
|
out_error:
|
|
/* undo tail page modifications made above */
|
|
p = page + 1;
|
|
for (j = 1; j < i; j++, p = mem_map_next(p, page, j)) {
|
|
clear_compound_head(p);
|
|
set_page_refcounted(p);
|
|
}
|
|
/* need to clear PG_reserved on remaining tail pages */
|
|
for (; j < nr_pages; j++, p = mem_map_next(p, page, j))
|
|
__ClearPageReserved(p);
|
|
set_compound_order(page, 0);
|
|
#ifdef CONFIG_64BIT
|
|
page[1].compound_nr = 0;
|
|
#endif
|
|
__ClearPageHead(page);
|
|
return false;
|
|
}
|
|
|
|
static bool prep_compound_gigantic_page(struct page *page, unsigned int order)
|
|
{
|
|
return __prep_compound_gigantic_page(page, order, false);
|
|
}
|
|
|
|
static bool prep_compound_gigantic_page_for_demote(struct page *page,
|
|
unsigned int order)
|
|
{
|
|
return __prep_compound_gigantic_page(page, order, true);
|
|
}
|
|
|
|
/*
|
|
* PageHuge() only returns true for hugetlbfs pages, but not for normal or
|
|
* transparent huge pages. See the PageTransHuge() documentation for more
|
|
* details.
|
|
*/
|
|
int PageHuge(struct page *page)
|
|
{
|
|
if (!PageCompound(page))
|
|
return 0;
|
|
|
|
page = compound_head(page);
|
|
return page[1].compound_dtor == HUGETLB_PAGE_DTOR;
|
|
}
|
|
EXPORT_SYMBOL_GPL(PageHuge);
|
|
|
|
/*
|
|
* PageHeadHuge() only returns true for hugetlbfs head page, but not for
|
|
* normal or transparent huge pages.
|
|
*/
|
|
int PageHeadHuge(struct page *page_head)
|
|
{
|
|
if (!PageHead(page_head))
|
|
return 0;
|
|
|
|
return page_head[1].compound_dtor == HUGETLB_PAGE_DTOR;
|
|
}
|
|
EXPORT_SYMBOL_GPL(PageHeadHuge);
|
|
|
|
/*
|
|
* Find and lock address space (mapping) in write mode.
|
|
*
|
|
* Upon entry, the page is locked which means that page_mapping() is
|
|
* stable. Due to locking order, we can only trylock_write. If we can
|
|
* not get the lock, simply return NULL to caller.
|
|
*/
|
|
struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage)
|
|
{
|
|
struct address_space *mapping = page_mapping(hpage);
|
|
|
|
if (!mapping)
|
|
return mapping;
|
|
|
|
if (i_mmap_trylock_write(mapping))
|
|
return mapping;
|
|
|
|
return NULL;
|
|
}
|
|
|
|
pgoff_t hugetlb_basepage_index(struct page *page)
|
|
{
|
|
struct page *page_head = compound_head(page);
|
|
pgoff_t index = page_index(page_head);
|
|
unsigned long compound_idx;
|
|
|
|
if (compound_order(page_head) >= MAX_ORDER)
|
|
compound_idx = page_to_pfn(page) - page_to_pfn(page_head);
|
|
else
|
|
compound_idx = page - page_head;
|
|
|
|
return (index << compound_order(page_head)) + compound_idx;
|
|
}
|
|
|
|
static struct page *alloc_buddy_huge_page(struct hstate *h,
|
|
gfp_t gfp_mask, int nid, nodemask_t *nmask,
|
|
nodemask_t *node_alloc_noretry)
|
|
{
|
|
int order = huge_page_order(h);
|
|
struct page *page;
|
|
bool alloc_try_hard = true;
|
|
|
|
/*
|
|
* By default we always try hard to allocate the page with
|
|
* __GFP_RETRY_MAYFAIL flag. However, if we are allocating pages in
|
|
* a loop (to adjust global huge page counts) and previous allocation
|
|
* failed, do not continue to try hard on the same node. Use the
|
|
* node_alloc_noretry bitmap to manage this state information.
|
|
*/
|
|
if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry))
|
|
alloc_try_hard = false;
|
|
gfp_mask |= __GFP_COMP|__GFP_NOWARN;
|
|
if (alloc_try_hard)
|
|
gfp_mask |= __GFP_RETRY_MAYFAIL;
|
|
if (nid == NUMA_NO_NODE)
|
|
nid = numa_mem_id();
|
|
page = __alloc_pages(gfp_mask, order, nid, nmask);
|
|
if (page)
|
|
__count_vm_event(HTLB_BUDDY_PGALLOC);
|
|
else
|
|
__count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
|
|
|
|
/*
|
|
* If we did not specify __GFP_RETRY_MAYFAIL, but still got a page this
|
|
* indicates an overall state change. Clear bit so that we resume
|
|
* normal 'try hard' allocations.
|
|
*/
|
|
if (node_alloc_noretry && page && !alloc_try_hard)
|
|
node_clear(nid, *node_alloc_noretry);
|
|
|
|
/*
|
|
* If we tried hard to get a page but failed, set bit so that
|
|
* subsequent attempts will not try as hard until there is an
|
|
* overall state change.
|
|
*/
|
|
if (node_alloc_noretry && !page && alloc_try_hard)
|
|
node_set(nid, *node_alloc_noretry);
|
|
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Common helper to allocate a fresh hugetlb page. All specific allocators
|
|
* should use this function to get new hugetlb pages
|
|
*/
|
|
static struct page *alloc_fresh_huge_page(struct hstate *h,
|
|
gfp_t gfp_mask, int nid, nodemask_t *nmask,
|
|
nodemask_t *node_alloc_noretry)
|
|
{
|
|
struct page *page;
|
|
bool retry = false;
|
|
|
|
retry:
|
|
if (hstate_is_gigantic(h))
|
|
page = alloc_gigantic_page(h, gfp_mask, nid, nmask);
|
|
else
|
|
page = alloc_buddy_huge_page(h, gfp_mask,
|
|
nid, nmask, node_alloc_noretry);
|
|
if (!page)
|
|
return NULL;
|
|
|
|
if (hstate_is_gigantic(h)) {
|
|
if (!prep_compound_gigantic_page(page, huge_page_order(h))) {
|
|
/*
|
|
* Rare failure to convert pages to compound page.
|
|
* Free pages and try again - ONCE!
|
|
*/
|
|
free_gigantic_page(page, huge_page_order(h));
|
|
if (!retry) {
|
|
retry = true;
|
|
goto retry;
|
|
}
|
|
return NULL;
|
|
}
|
|
}
|
|
prep_new_huge_page(h, page, page_to_nid(page));
|
|
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Allocates a fresh page to the hugetlb allocator pool in the node interleaved
|
|
* manner.
|
|
*/
|
|
static int alloc_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed,
|
|
nodemask_t *node_alloc_noretry)
|
|
{
|
|
struct page *page;
|
|
int nr_nodes, node;
|
|
gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
|
|
|
|
for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
|
|
page = alloc_fresh_huge_page(h, gfp_mask, node, nodes_allowed,
|
|
node_alloc_noretry);
|
|
if (page)
|
|
break;
|
|
}
|
|
|
|
if (!page)
|
|
return 0;
|
|
|
|
put_page(page); /* free it into the hugepage allocator */
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Remove huge page from pool from next node to free. Attempt to keep
|
|
* persistent huge pages more or less balanced over allowed nodes.
|
|
* This routine only 'removes' the hugetlb page. The caller must make
|
|
* an additional call to free the page to low level allocators.
|
|
* Called with hugetlb_lock locked.
|
|
*/
|
|
static struct page *remove_pool_huge_page(struct hstate *h,
|
|
nodemask_t *nodes_allowed,
|
|
bool acct_surplus)
|
|
{
|
|
int nr_nodes, node;
|
|
struct page *page = NULL;
|
|
|
|
lockdep_assert_held(&hugetlb_lock);
|
|
for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) {
|
|
/*
|
|
* If we're returning unused surplus pages, only examine
|
|
* nodes with surplus pages.
|
|
*/
|
|
if ((!acct_surplus || h->surplus_huge_pages_node[node]) &&
|
|
!list_empty(&h->hugepage_freelists[node])) {
|
|
page = list_entry(h->hugepage_freelists[node].next,
|
|
struct page, lru);
|
|
remove_hugetlb_page(h, page, acct_surplus);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Dissolve a given free hugepage into free buddy pages. This function does
|
|
* nothing for in-use hugepages and non-hugepages.
|
|
* This function returns values like below:
|
|
*
|
|
* -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages
|
|
* when the system is under memory pressure and the feature of
|
|
* freeing unused vmemmap pages associated with each hugetlb page
|
|
* is enabled.
|
|
* -EBUSY: failed to dissolved free hugepages or the hugepage is in-use
|
|
* (allocated or reserved.)
|
|
* 0: successfully dissolved free hugepages or the page is not a
|
|
* hugepage (considered as already dissolved)
|
|
*/
|
|
int dissolve_free_huge_page(struct page *page)
|
|
{
|
|
int rc = -EBUSY;
|
|
|
|
retry:
|
|
/* Not to disrupt normal path by vainly holding hugetlb_lock */
|
|
if (!PageHuge(page))
|
|
return 0;
|
|
|
|
spin_lock_irq(&hugetlb_lock);
|
|
if (!PageHuge(page)) {
|
|
rc = 0;
|
|
goto out;
|
|
}
|
|
|
|
if (!page_count(page)) {
|
|
struct page *head = compound_head(page);
|
|
struct hstate *h = page_hstate(head);
|
|
if (h->free_huge_pages - h->resv_huge_pages == 0)
|
|
goto out;
|
|
|
|
/*
|
|
* We should make sure that the page is already on the free list
|
|
* when it is dissolved.
|
|
*/
|
|
if (unlikely(!HPageFreed(head))) {
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
cond_resched();
|
|
|
|
/*
|
|
* Theoretically, we should return -EBUSY when we
|
|
* encounter this race. In fact, we have a chance
|
|
* to successfully dissolve the page if we do a
|
|
* retry. Because the race window is quite small.
|
|
* If we seize this opportunity, it is an optimization
|
|
* for increasing the success rate of dissolving page.
|
|
*/
|
|
goto retry;
|
|
}
|
|
|
|
remove_hugetlb_page(h, head, false);
|
|
h->max_huge_pages--;
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
|
|
/*
|
|
* Normally update_and_free_page will allocate required vmemmmap
|
|
* before freeing the page. update_and_free_page will fail to
|
|
* free the page if it can not allocate required vmemmap. We
|
|
* need to adjust max_huge_pages if the page is not freed.
|
|
* Attempt to allocate vmemmmap here so that we can take
|
|
* appropriate action on failure.
|
|
*/
|
|
rc = hugetlb_vmemmap_alloc(h, head);
|
|
if (!rc) {
|
|
/*
|
|
* Move PageHWPoison flag from head page to the raw
|
|
* error page, which makes any subpages rather than
|
|
* the error page reusable.
|
|
*/
|
|
if (PageHWPoison(head) && page != head) {
|
|
SetPageHWPoison(page);
|
|
ClearPageHWPoison(head);
|
|
}
|
|
update_and_free_page(h, head, false);
|
|
} else {
|
|
spin_lock_irq(&hugetlb_lock);
|
|
add_hugetlb_page(h, head, false);
|
|
h->max_huge_pages++;
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
out:
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Dissolve free hugepages in a given pfn range. Used by memory hotplug to
|
|
* make specified memory blocks removable from the system.
|
|
* Note that this will dissolve a free gigantic hugepage completely, if any
|
|
* part of it lies within the given range.
|
|
* Also note that if dissolve_free_huge_page() returns with an error, all
|
|
* free hugepages that were dissolved before that error are lost.
|
|
*/
|
|
int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn)
|
|
{
|
|
unsigned long pfn;
|
|
struct page *page;
|
|
int rc = 0;
|
|
|
|
if (!hugepages_supported())
|
|
return rc;
|
|
|
|
for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order) {
|
|
page = pfn_to_page(pfn);
|
|
rc = dissolve_free_huge_page(page);
|
|
if (rc)
|
|
break;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Allocates a fresh surplus page from the page allocator.
|
|
*/
|
|
static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask,
|
|
int nid, nodemask_t *nmask, bool zero_ref)
|
|
{
|
|
struct page *page = NULL;
|
|
bool retry = false;
|
|
|
|
if (hstate_is_gigantic(h))
|
|
return NULL;
|
|
|
|
spin_lock_irq(&hugetlb_lock);
|
|
if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages)
|
|
goto out_unlock;
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
|
|
retry:
|
|
page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL);
|
|
if (!page)
|
|
return NULL;
|
|
|
|
spin_lock_irq(&hugetlb_lock);
|
|
/*
|
|
* We could have raced with the pool size change.
|
|
* Double check that and simply deallocate the new page
|
|
* if we would end up overcommiting the surpluses. Abuse
|
|
* temporary page to workaround the nasty free_huge_page
|
|
* codeflow
|
|
*/
|
|
if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
|
|
SetHPageTemporary(page);
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
put_page(page);
|
|
return NULL;
|
|
}
|
|
|
|
if (zero_ref) {
|
|
/*
|
|
* Caller requires a page with zero ref count.
|
|
* We will drop ref count here. If someone else is holding
|
|
* a ref, the page will be freed when they drop it. Abuse
|
|
* temporary page flag to accomplish this.
|
|
*/
|
|
SetHPageTemporary(page);
|
|
if (!put_page_testzero(page)) {
|
|
/*
|
|
* Unexpected inflated ref count on freshly allocated
|
|
* huge. Retry once.
|
|
*/
|
|
pr_info("HugeTLB unexpected inflated ref count on freshly allocated page\n");
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
if (retry)
|
|
return NULL;
|
|
|
|
retry = true;
|
|
goto retry;
|
|
}
|
|
ClearHPageTemporary(page);
|
|
}
|
|
|
|
h->surplus_huge_pages++;
|
|
h->surplus_huge_pages_node[page_to_nid(page)]++;
|
|
|
|
out_unlock:
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
|
|
return page;
|
|
}
|
|
|
|
static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
|
|
int nid, nodemask_t *nmask)
|
|
{
|
|
struct page *page;
|
|
|
|
if (hstate_is_gigantic(h))
|
|
return NULL;
|
|
|
|
page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL);
|
|
if (!page)
|
|
return NULL;
|
|
|
|
/*
|
|
* We do not account these pages as surplus because they are only
|
|
* temporary and will be released properly on the last reference
|
|
*/
|
|
SetHPageTemporary(page);
|
|
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Use the VMA's mpolicy to allocate a huge page from the buddy.
|
|
*/
|
|
static
|
|
struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
struct page *page = NULL;
|
|
struct mempolicy *mpol;
|
|
gfp_t gfp_mask = htlb_alloc_mask(h);
|
|
int nid;
|
|
nodemask_t *nodemask;
|
|
|
|
nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask);
|
|
if (mpol_is_preferred_many(mpol)) {
|
|
gfp_t gfp = gfp_mask | __GFP_NOWARN;
|
|
|
|
gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL);
|
|
page = alloc_surplus_huge_page(h, gfp, nid, nodemask, false);
|
|
|
|
/* Fallback to all nodes if page==NULL */
|
|
nodemask = NULL;
|
|
}
|
|
|
|
if (!page)
|
|
page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask, false);
|
|
mpol_cond_put(mpol);
|
|
return page;
|
|
}
|
|
|
|
/* page migration callback function */
|
|
struct page *alloc_huge_page_nodemask(struct hstate *h, int preferred_nid,
|
|
nodemask_t *nmask, gfp_t gfp_mask)
|
|
{
|
|
spin_lock_irq(&hugetlb_lock);
|
|
if (h->free_huge_pages - h->resv_huge_pages > 0) {
|
|
struct page *page;
|
|
|
|
page = dequeue_huge_page_nodemask(h, gfp_mask, preferred_nid, nmask);
|
|
if (page) {
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
return page;
|
|
}
|
|
}
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
|
|
return alloc_migrate_huge_page(h, gfp_mask, preferred_nid, nmask);
|
|
}
|
|
|
|
/* mempolicy aware migration callback */
|
|
struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma,
|
|
unsigned long address)
|
|
{
|
|
struct mempolicy *mpol;
|
|
nodemask_t *nodemask;
|
|
struct page *page;
|
|
gfp_t gfp_mask;
|
|
int node;
|
|
|
|
gfp_mask = htlb_alloc_mask(h);
|
|
node = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
|
|
page = alloc_huge_page_nodemask(h, node, nodemask, gfp_mask);
|
|
mpol_cond_put(mpol);
|
|
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Increase the hugetlb pool such that it can accommodate a reservation
|
|
* of size 'delta'.
|
|
*/
|
|
static int gather_surplus_pages(struct hstate *h, long delta)
|
|
__must_hold(&hugetlb_lock)
|
|
{
|
|
struct list_head surplus_list;
|
|
struct page *page, *tmp;
|
|
int ret;
|
|
long i;
|
|
long needed, allocated;
|
|
bool alloc_ok = true;
|
|
|
|
lockdep_assert_held(&hugetlb_lock);
|
|
needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
|
|
if (needed <= 0) {
|
|
h->resv_huge_pages += delta;
|
|
return 0;
|
|
}
|
|
|
|
allocated = 0;
|
|
INIT_LIST_HEAD(&surplus_list);
|
|
|
|
ret = -ENOMEM;
|
|
retry:
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
for (i = 0; i < needed; i++) {
|
|
page = alloc_surplus_huge_page(h, htlb_alloc_mask(h),
|
|
NUMA_NO_NODE, NULL, true);
|
|
if (!page) {
|
|
alloc_ok = false;
|
|
break;
|
|
}
|
|
list_add(&page->lru, &surplus_list);
|
|
cond_resched();
|
|
}
|
|
allocated += i;
|
|
|
|
/*
|
|
* After retaking hugetlb_lock, we need to recalculate 'needed'
|
|
* because either resv_huge_pages or free_huge_pages may have changed.
|
|
*/
|
|
spin_lock_irq(&hugetlb_lock);
|
|
needed = (h->resv_huge_pages + delta) -
|
|
(h->free_huge_pages + allocated);
|
|
if (needed > 0) {
|
|
if (alloc_ok)
|
|
goto retry;
|
|
/*
|
|
* We were not able to allocate enough pages to
|
|
* satisfy the entire reservation so we free what
|
|
* we've allocated so far.
|
|
*/
|
|
goto free;
|
|
}
|
|
/*
|
|
* The surplus_list now contains _at_least_ the number of extra pages
|
|
* needed to accommodate the reservation. Add the appropriate number
|
|
* of pages to the hugetlb pool and free the extras back to the buddy
|
|
* allocator. Commit the entire reservation here to prevent another
|
|
* process from stealing the pages as they are added to the pool but
|
|
* before they are reserved.
|
|
*/
|
|
needed += allocated;
|
|
h->resv_huge_pages += delta;
|
|
ret = 0;
|
|
|
|
/* Free the needed pages to the hugetlb pool */
|
|
list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
|
|
if ((--needed) < 0)
|
|
break;
|
|
/* Add the page to the hugetlb allocator */
|
|
enqueue_huge_page(h, page);
|
|
}
|
|
free:
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
|
|
/*
|
|
* Free unnecessary surplus pages to the buddy allocator.
|
|
* Pages have no ref count, call free_huge_page directly.
|
|
*/
|
|
list_for_each_entry_safe(page, tmp, &surplus_list, lru)
|
|
free_huge_page(page);
|
|
spin_lock_irq(&hugetlb_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* This routine has two main purposes:
|
|
* 1) Decrement the reservation count (resv_huge_pages) by the value passed
|
|
* in unused_resv_pages. This corresponds to the prior adjustments made
|
|
* to the associated reservation map.
|
|
* 2) Free any unused surplus pages that may have been allocated to satisfy
|
|
* the reservation. As many as unused_resv_pages may be freed.
|
|
*/
|
|
static void return_unused_surplus_pages(struct hstate *h,
|
|
unsigned long unused_resv_pages)
|
|
{
|
|
unsigned long nr_pages;
|
|
struct page *page;
|
|
LIST_HEAD(page_list);
|
|
|
|
lockdep_assert_held(&hugetlb_lock);
|
|
/* Uncommit the reservation */
|
|
h->resv_huge_pages -= unused_resv_pages;
|
|
|
|
/* Cannot return gigantic pages currently */
|
|
if (hstate_is_gigantic(h))
|
|
goto out;
|
|
|
|
/*
|
|
* Part (or even all) of the reservation could have been backed
|
|
* by pre-allocated pages. Only free surplus pages.
|
|
*/
|
|
nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
|
|
|
|
/*
|
|
* We want to release as many surplus pages as possible, spread
|
|
* evenly across all nodes with memory. Iterate across these nodes
|
|
* until we can no longer free unreserved surplus pages. This occurs
|
|
* when the nodes with surplus pages have no free pages.
|
|
* remove_pool_huge_page() will balance the freed pages across the
|
|
* on-line nodes with memory and will handle the hstate accounting.
|
|
*/
|
|
while (nr_pages--) {
|
|
page = remove_pool_huge_page(h, &node_states[N_MEMORY], 1);
|
|
if (!page)
|
|
goto out;
|
|
|
|
list_add(&page->lru, &page_list);
|
|
}
|
|
|
|
out:
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
update_and_free_pages_bulk(h, &page_list);
|
|
spin_lock_irq(&hugetlb_lock);
|
|
}
|
|
|
|
|
|
/*
|
|
* vma_needs_reservation, vma_commit_reservation and vma_end_reservation
|
|
* are used by the huge page allocation routines to manage reservations.
|
|
*
|
|
* vma_needs_reservation is called to determine if the huge page at addr
|
|
* within the vma has an associated reservation. If a reservation is
|
|
* needed, the value 1 is returned. The caller is then responsible for
|
|
* managing the global reservation and subpool usage counts. After
|
|
* the huge page has been allocated, vma_commit_reservation is called
|
|
* to add the page to the reservation map. If the page allocation fails,
|
|
* the reservation must be ended instead of committed. vma_end_reservation
|
|
* is called in such cases.
|
|
*
|
|
* In the normal case, vma_commit_reservation returns the same value
|
|
* as the preceding vma_needs_reservation call. The only time this
|
|
* is not the case is if a reserve map was changed between calls. It
|
|
* is the responsibility of the caller to notice the difference and
|
|
* take appropriate action.
|
|
*
|
|
* vma_add_reservation is used in error paths where a reservation must
|
|
* be restored when a newly allocated huge page must be freed. It is
|
|
* to be called after calling vma_needs_reservation to determine if a
|
|
* reservation exists.
|
|
*
|
|
* vma_del_reservation is used in error paths where an entry in the reserve
|
|
* map was created during huge page allocation and must be removed. It is to
|
|
* be called after calling vma_needs_reservation to determine if a reservation
|
|
* exists.
|
|
*/
|
|
enum vma_resv_mode {
|
|
VMA_NEEDS_RESV,
|
|
VMA_COMMIT_RESV,
|
|
VMA_END_RESV,
|
|
VMA_ADD_RESV,
|
|
VMA_DEL_RESV,
|
|
};
|
|
static long __vma_reservation_common(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long addr,
|
|
enum vma_resv_mode mode)
|
|
{
|
|
struct resv_map *resv;
|
|
pgoff_t idx;
|
|
long ret;
|
|
long dummy_out_regions_needed;
|
|
|
|
resv = vma_resv_map(vma);
|
|
if (!resv)
|
|
return 1;
|
|
|
|
idx = vma_hugecache_offset(h, vma, addr);
|
|
switch (mode) {
|
|
case VMA_NEEDS_RESV:
|
|
ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed);
|
|
/* We assume that vma_reservation_* routines always operate on
|
|
* 1 page, and that adding to resv map a 1 page entry can only
|
|
* ever require 1 region.
|
|
*/
|
|
VM_BUG_ON(dummy_out_regions_needed != 1);
|
|
break;
|
|
case VMA_COMMIT_RESV:
|
|
ret = region_add(resv, idx, idx + 1, 1, NULL, NULL);
|
|
/* region_add calls of range 1 should never fail. */
|
|
VM_BUG_ON(ret < 0);
|
|
break;
|
|
case VMA_END_RESV:
|
|
region_abort(resv, idx, idx + 1, 1);
|
|
ret = 0;
|
|
break;
|
|
case VMA_ADD_RESV:
|
|
if (vma->vm_flags & VM_MAYSHARE) {
|
|
ret = region_add(resv, idx, idx + 1, 1, NULL, NULL);
|
|
/* region_add calls of range 1 should never fail. */
|
|
VM_BUG_ON(ret < 0);
|
|
} else {
|
|
region_abort(resv, idx, idx + 1, 1);
|
|
ret = region_del(resv, idx, idx + 1);
|
|
}
|
|
break;
|
|
case VMA_DEL_RESV:
|
|
if (vma->vm_flags & VM_MAYSHARE) {
|
|
region_abort(resv, idx, idx + 1, 1);
|
|
ret = region_del(resv, idx, idx + 1);
|
|
} else {
|
|
ret = region_add(resv, idx, idx + 1, 1, NULL, NULL);
|
|
/* region_add calls of range 1 should never fail. */
|
|
VM_BUG_ON(ret < 0);
|
|
}
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
if (vma->vm_flags & VM_MAYSHARE || mode == VMA_DEL_RESV)
|
|
return ret;
|
|
/*
|
|
* We know private mapping must have HPAGE_RESV_OWNER set.
|
|
*
|
|
* In most cases, reserves always exist for private mappings.
|
|
* However, a file associated with mapping could have been
|
|
* hole punched or truncated after reserves were consumed.
|
|
* As subsequent fault on such a range will not use reserves.
|
|
* Subtle - The reserve map for private mappings has the
|
|
* opposite meaning than that of shared mappings. If NO
|
|
* entry is in the reserve map, it means a reservation exists.
|
|
* If an entry exists in the reserve map, it means the
|
|
* reservation has already been consumed. As a result, the
|
|
* return value of this routine is the opposite of the
|
|
* value returned from reserve map manipulation routines above.
|
|
*/
|
|
if (ret > 0)
|
|
return 0;
|
|
if (ret == 0)
|
|
return 1;
|
|
return ret;
|
|
}
|
|
|
|
static long vma_needs_reservation(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV);
|
|
}
|
|
|
|
static long vma_commit_reservation(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV);
|
|
}
|
|
|
|
static void vma_end_reservation(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
(void)__vma_reservation_common(h, vma, addr, VMA_END_RESV);
|
|
}
|
|
|
|
static long vma_add_reservation(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV);
|
|
}
|
|
|
|
static long vma_del_reservation(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
return __vma_reservation_common(h, vma, addr, VMA_DEL_RESV);
|
|
}
|
|
|
|
/*
|
|
* This routine is called to restore reservation information on error paths.
|
|
* It should ONLY be called for pages allocated via alloc_huge_page(), and
|
|
* the hugetlb mutex should remain held when calling this routine.
|
|
*
|
|
* It handles two specific cases:
|
|
* 1) A reservation was in place and the page consumed the reservation.
|
|
* HPageRestoreReserve is set in the page.
|
|
* 2) No reservation was in place for the page, so HPageRestoreReserve is
|
|
* not set. However, alloc_huge_page always updates the reserve map.
|
|
*
|
|
* In case 1, free_huge_page later in the error path will increment the
|
|
* global reserve count. But, free_huge_page does not have enough context
|
|
* to adjust the reservation map. This case deals primarily with private
|
|
* mappings. Adjust the reserve map here to be consistent with global
|
|
* reserve count adjustments to be made by free_huge_page. Make sure the
|
|
* reserve map indicates there is a reservation present.
|
|
*
|
|
* In case 2, simply undo reserve map modifications done by alloc_huge_page.
|
|
*/
|
|
void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma,
|
|
unsigned long address, struct page *page)
|
|
{
|
|
long rc = vma_needs_reservation(h, vma, address);
|
|
|
|
if (HPageRestoreReserve(page)) {
|
|
if (unlikely(rc < 0))
|
|
/*
|
|
* Rare out of memory condition in reserve map
|
|
* manipulation. Clear HPageRestoreReserve so that
|
|
* global reserve count will not be incremented
|
|
* by free_huge_page. This will make it appear
|
|
* as though the reservation for this page was
|
|
* consumed. This may prevent the task from
|
|
* faulting in the page at a later time. This
|
|
* is better than inconsistent global huge page
|
|
* accounting of reserve counts.
|
|
*/
|
|
ClearHPageRestoreReserve(page);
|
|
else if (rc)
|
|
(void)vma_add_reservation(h, vma, address);
|
|
else
|
|
vma_end_reservation(h, vma, address);
|
|
} else {
|
|
if (!rc) {
|
|
/*
|
|
* This indicates there is an entry in the reserve map
|
|
* not added by alloc_huge_page. We know it was added
|
|
* before the alloc_huge_page call, otherwise
|
|
* HPageRestoreReserve would be set on the page.
|
|
* Remove the entry so that a subsequent allocation
|
|
* does not consume a reservation.
|
|
*/
|
|
rc = vma_del_reservation(h, vma, address);
|
|
if (rc < 0)
|
|
/*
|
|
* VERY rare out of memory condition. Since
|
|
* we can not delete the entry, set
|
|
* HPageRestoreReserve so that the reserve
|
|
* count will be incremented when the page
|
|
* is freed. This reserve will be consumed
|
|
* on a subsequent allocation.
|
|
*/
|
|
SetHPageRestoreReserve(page);
|
|
} else if (rc < 0) {
|
|
/*
|
|
* Rare out of memory condition from
|
|
* vma_needs_reservation call. Memory allocation is
|
|
* only attempted if a new entry is needed. Therefore,
|
|
* this implies there is not an entry in the
|
|
* reserve map.
|
|
*
|
|
* For shared mappings, no entry in the map indicates
|
|
* no reservation. We are done.
|
|
*/
|
|
if (!(vma->vm_flags & VM_MAYSHARE))
|
|
/*
|
|
* For private mappings, no entry indicates
|
|
* a reservation is present. Since we can
|
|
* not add an entry, set SetHPageRestoreReserve
|
|
* on the page so reserve count will be
|
|
* incremented when freed. This reserve will
|
|
* be consumed on a subsequent allocation.
|
|
*/
|
|
SetHPageRestoreReserve(page);
|
|
} else
|
|
/*
|
|
* No reservation present, do nothing
|
|
*/
|
|
vma_end_reservation(h, vma, address);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* alloc_and_dissolve_huge_page - Allocate a new page and dissolve the old one
|
|
* @h: struct hstate old page belongs to
|
|
* @old_page: Old page to dissolve
|
|
* @list: List to isolate the page in case we need to
|
|
* Returns 0 on success, otherwise negated error.
|
|
*/
|
|
static int alloc_and_dissolve_huge_page(struct hstate *h, struct page *old_page,
|
|
struct list_head *list)
|
|
{
|
|
gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
|
|
int nid = page_to_nid(old_page);
|
|
bool alloc_retry = false;
|
|
struct page *new_page;
|
|
int ret = 0;
|
|
|
|
/*
|
|
* Before dissolving the page, we need to allocate a new one for the
|
|
* pool to remain stable. Here, we allocate the page and 'prep' it
|
|
* by doing everything but actually updating counters and adding to
|
|
* the pool. This simplifies and let us do most of the processing
|
|
* under the lock.
|
|
*/
|
|
alloc_retry:
|
|
new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL);
|
|
if (!new_page)
|
|
return -ENOMEM;
|
|
/*
|
|
* If all goes well, this page will be directly added to the free
|
|
* list in the pool. For this the ref count needs to be zero.
|
|
* Attempt to drop now, and retry once if needed. It is VERY
|
|
* unlikely there is another ref on the page.
|
|
*
|
|
* If someone else has a reference to the page, it will be freed
|
|
* when they drop their ref. Abuse temporary page flag to accomplish
|
|
* this. Retry once if there is an inflated ref count.
|
|
*/
|
|
SetHPageTemporary(new_page);
|
|
if (!put_page_testzero(new_page)) {
|
|
if (alloc_retry)
|
|
return -EBUSY;
|
|
|
|
alloc_retry = true;
|
|
goto alloc_retry;
|
|
}
|
|
ClearHPageTemporary(new_page);
|
|
|
|
__prep_new_huge_page(h, new_page);
|
|
|
|
retry:
|
|
spin_lock_irq(&hugetlb_lock);
|
|
if (!PageHuge(old_page)) {
|
|
/*
|
|
* Freed from under us. Drop new_page too.
|
|
*/
|
|
goto free_new;
|
|
} else if (page_count(old_page)) {
|
|
/*
|
|
* Someone has grabbed the page, try to isolate it here.
|
|
* Fail with -EBUSY if not possible.
|
|
*/
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
if (!isolate_huge_page(old_page, list))
|
|
ret = -EBUSY;
|
|
spin_lock_irq(&hugetlb_lock);
|
|
goto free_new;
|
|
} else if (!HPageFreed(old_page)) {
|
|
/*
|
|
* Page's refcount is 0 but it has not been enqueued in the
|
|
* freelist yet. Race window is small, so we can succeed here if
|
|
* we retry.
|
|
*/
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
cond_resched();
|
|
goto retry;
|
|
} else {
|
|
/*
|
|
* Ok, old_page is still a genuine free hugepage. Remove it from
|
|
* the freelist and decrease the counters. These will be
|
|
* incremented again when calling __prep_account_new_huge_page()
|
|
* and enqueue_huge_page() for new_page. The counters will remain
|
|
* stable since this happens under the lock.
|
|
*/
|
|
remove_hugetlb_page(h, old_page, false);
|
|
|
|
/*
|
|
* Ref count on new page is already zero as it was dropped
|
|
* earlier. It can be directly added to the pool free list.
|
|
*/
|
|
__prep_account_new_huge_page(h, nid);
|
|
enqueue_huge_page(h, new_page);
|
|
|
|
/*
|
|
* Pages have been replaced, we can safely free the old one.
|
|
*/
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
update_and_free_page(h, old_page, false);
|
|
}
|
|
|
|
return ret;
|
|
|
|
free_new:
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
/* Page has a zero ref count, but needs a ref to be freed */
|
|
set_page_refcounted(new_page);
|
|
update_and_free_page(h, new_page, false);
|
|
|
|
return ret;
|
|
}
|
|
|
|
int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
|
|
{
|
|
struct hstate *h;
|
|
struct page *head;
|
|
int ret = -EBUSY;
|
|
|
|
/*
|
|
* The page might have been dissolved from under our feet, so make sure
|
|
* to carefully check the state under the lock.
|
|
* Return success when racing as if we dissolved the page ourselves.
|
|
*/
|
|
spin_lock_irq(&hugetlb_lock);
|
|
if (PageHuge(page)) {
|
|
head = compound_head(page);
|
|
h = page_hstate(head);
|
|
} else {
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
return 0;
|
|
}
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
|
|
/*
|
|
* Fence off gigantic pages as there is a cyclic dependency between
|
|
* alloc_contig_range and them. Return -ENOMEM as this has the effect
|
|
* of bailing out right away without further retrying.
|
|
*/
|
|
if (hstate_is_gigantic(h))
|
|
return -ENOMEM;
|
|
|
|
if (page_count(head) && isolate_huge_page(head, list))
|
|
ret = 0;
|
|
else if (!page_count(head))
|
|
ret = alloc_and_dissolve_huge_page(h, head, list);
|
|
|
|
return ret;
|
|
}
|
|
|
|
struct page *alloc_huge_page(struct vm_area_struct *vma,
|
|
unsigned long addr, int avoid_reserve)
|
|
{
|
|
struct hugepage_subpool *spool = subpool_vma(vma);
|
|
struct hstate *h = hstate_vma(vma);
|
|
struct page *page;
|
|
long map_chg, map_commit;
|
|
long gbl_chg;
|
|
int ret, idx;
|
|
struct hugetlb_cgroup *h_cg;
|
|
bool deferred_reserve;
|
|
|
|
idx = hstate_index(h);
|
|
/*
|
|
* Examine the region/reserve map to determine if the process
|
|
* has a reservation for the page to be allocated. A return
|
|
* code of zero indicates a reservation exists (no change).
|
|
*/
|
|
map_chg = gbl_chg = vma_needs_reservation(h, vma, addr);
|
|
if (map_chg < 0)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
/*
|
|
* Processes that did not create the mapping will have no
|
|
* reserves as indicated by the region/reserve map. Check
|
|
* that the allocation will not exceed the subpool limit.
|
|
* Allocations for MAP_NORESERVE mappings also need to be
|
|
* checked against any subpool limit.
|
|
*/
|
|
if (map_chg || avoid_reserve) {
|
|
gbl_chg = hugepage_subpool_get_pages(spool, 1);
|
|
if (gbl_chg < 0) {
|
|
vma_end_reservation(h, vma, addr);
|
|
return ERR_PTR(-ENOSPC);
|
|
}
|
|
|
|
/*
|
|
* Even though there was no reservation in the region/reserve
|
|
* map, there could be reservations associated with the
|
|
* subpool that can be used. This would be indicated if the
|
|
* return value of hugepage_subpool_get_pages() is zero.
|
|
* However, if avoid_reserve is specified we still avoid even
|
|
* the subpool reservations.
|
|
*/
|
|
if (avoid_reserve)
|
|
gbl_chg = 1;
|
|
}
|
|
|
|
/* If this allocation is not consuming a reservation, charge it now.
|
|
*/
|
|
deferred_reserve = map_chg || avoid_reserve;
|
|
if (deferred_reserve) {
|
|
ret = hugetlb_cgroup_charge_cgroup_rsvd(
|
|
idx, pages_per_huge_page(h), &h_cg);
|
|
if (ret)
|
|
goto out_subpool_put;
|
|
}
|
|
|
|
ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg);
|
|
if (ret)
|
|
goto out_uncharge_cgroup_reservation;
|
|
|
|
spin_lock_irq(&hugetlb_lock);
|
|
/*
|
|
* glb_chg is passed to indicate whether or not a page must be taken
|
|
* from the global free pool (global change). gbl_chg == 0 indicates
|
|
* a reservation exists for the allocation.
|
|
*/
|
|
page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg);
|
|
if (!page) {
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
page = alloc_buddy_huge_page_with_mpol(h, vma, addr);
|
|
if (!page)
|
|
goto out_uncharge_cgroup;
|
|
if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) {
|
|
SetHPageRestoreReserve(page);
|
|
h->resv_huge_pages--;
|
|
}
|
|
spin_lock_irq(&hugetlb_lock);
|
|
list_add(&page->lru, &h->hugepage_activelist);
|
|
/* Fall through */
|
|
}
|
|
hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page);
|
|
/* If allocation is not consuming a reservation, also store the
|
|
* hugetlb_cgroup pointer on the page.
|
|
*/
|
|
if (deferred_reserve) {
|
|
hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h),
|
|
h_cg, page);
|
|
}
|
|
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
|
|
hugetlb_set_page_subpool(page, spool);
|
|
|
|
map_commit = vma_commit_reservation(h, vma, addr);
|
|
if (unlikely(map_chg > map_commit)) {
|
|
/*
|
|
* The page was added to the reservation map between
|
|
* vma_needs_reservation and vma_commit_reservation.
|
|
* This indicates a race with hugetlb_reserve_pages.
|
|
* Adjust for the subpool count incremented above AND
|
|
* in hugetlb_reserve_pages for the same page. Also,
|
|
* the reservation count added in hugetlb_reserve_pages
|
|
* no longer applies.
|
|
*/
|
|
long rsv_adjust;
|
|
|
|
rsv_adjust = hugepage_subpool_put_pages(spool, 1);
|
|
hugetlb_acct_memory(h, -rsv_adjust);
|
|
if (deferred_reserve)
|
|
hugetlb_cgroup_uncharge_page_rsvd(hstate_index(h),
|
|
pages_per_huge_page(h), page);
|
|
}
|
|
return page;
|
|
|
|
out_uncharge_cgroup:
|
|
hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg);
|
|
out_uncharge_cgroup_reservation:
|
|
if (deferred_reserve)
|
|
hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h),
|
|
h_cg);
|
|
out_subpool_put:
|
|
if (map_chg || avoid_reserve)
|
|
hugepage_subpool_put_pages(spool, 1);
|
|
vma_end_reservation(h, vma, addr);
|
|
return ERR_PTR(-ENOSPC);
|
|
}
|
|
|
|
int alloc_bootmem_huge_page(struct hstate *h, int nid)
|
|
__attribute__ ((weak, alias("__alloc_bootmem_huge_page")));
|
|
int __alloc_bootmem_huge_page(struct hstate *h, int nid)
|
|
{
|
|
struct huge_bootmem_page *m = NULL; /* initialize for clang */
|
|
int nr_nodes, node;
|
|
|
|
/* do node specific alloc */
|
|
if (nid != NUMA_NO_NODE) {
|
|
m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h),
|
|
0, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
|
|
if (!m)
|
|
return 0;
|
|
goto found;
|
|
}
|
|
/* allocate from next node when distributing huge pages */
|
|
for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
|
|
m = memblock_alloc_try_nid_raw(
|
|
huge_page_size(h), huge_page_size(h),
|
|
0, MEMBLOCK_ALLOC_ACCESSIBLE, node);
|
|
/*
|
|
* Use the beginning of the huge page to store the
|
|
* huge_bootmem_page struct (until gather_bootmem
|
|
* puts them into the mem_map).
|
|
*/
|
|
if (!m)
|
|
return 0;
|
|
goto found;
|
|
}
|
|
|
|
found:
|
|
/* Put them into a private list first because mem_map is not up yet */
|
|
INIT_LIST_HEAD(&m->list);
|
|
list_add(&m->list, &huge_boot_pages);
|
|
m->hstate = h;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Put bootmem huge pages into the standard lists after mem_map is up.
|
|
* Note: This only applies to gigantic (order > MAX_ORDER) pages.
|
|
*/
|
|
static void __init gather_bootmem_prealloc(void)
|
|
{
|
|
struct huge_bootmem_page *m;
|
|
|
|
list_for_each_entry(m, &huge_boot_pages, list) {
|
|
struct page *page = virt_to_page(m);
|
|
struct hstate *h = m->hstate;
|
|
|
|
VM_BUG_ON(!hstate_is_gigantic(h));
|
|
WARN_ON(page_count(page) != 1);
|
|
if (prep_compound_gigantic_page(page, huge_page_order(h))) {
|
|
WARN_ON(PageReserved(page));
|
|
prep_new_huge_page(h, page, page_to_nid(page));
|
|
put_page(page); /* add to the hugepage allocator */
|
|
} else {
|
|
/* VERY unlikely inflated ref count on a tail page */
|
|
free_gigantic_page(page, huge_page_order(h));
|
|
}
|
|
|
|
/*
|
|
* We need to restore the 'stolen' pages to totalram_pages
|
|
* in order to fix confusing memory reports from free(1) and
|
|
* other side-effects, like CommitLimit going negative.
|
|
*/
|
|
adjust_managed_page_count(page, pages_per_huge_page(h));
|
|
cond_resched();
|
|
}
|
|
}
|
|
static void __init hugetlb_hstate_alloc_pages_onenode(struct hstate *h, int nid)
|
|
{
|
|
unsigned long i;
|
|
char buf[32];
|
|
|
|
for (i = 0; i < h->max_huge_pages_node[nid]; ++i) {
|
|
if (hstate_is_gigantic(h)) {
|
|
if (!alloc_bootmem_huge_page(h, nid))
|
|
break;
|
|
} else {
|
|
struct page *page;
|
|
gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
|
|
|
|
page = alloc_fresh_huge_page(h, gfp_mask, nid,
|
|
&node_states[N_MEMORY], NULL);
|
|
if (!page)
|
|
break;
|
|
put_page(page); /* free it into the hugepage allocator */
|
|
}
|
|
cond_resched();
|
|
}
|
|
if (i == h->max_huge_pages_node[nid])
|
|
return;
|
|
|
|
string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32);
|
|
pr_warn("HugeTLB: allocating %u of page size %s failed node%d. Only allocated %lu hugepages.\n",
|
|
h->max_huge_pages_node[nid], buf, nid, i);
|
|
h->max_huge_pages -= (h->max_huge_pages_node[nid] - i);
|
|
h->max_huge_pages_node[nid] = i;
|
|
}
|
|
|
|
static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
|
|
{
|
|
unsigned long i;
|
|
nodemask_t *node_alloc_noretry;
|
|
bool node_specific_alloc = false;
|
|
|
|
/* skip gigantic hugepages allocation if hugetlb_cma enabled */
|
|
if (hstate_is_gigantic(h) && hugetlb_cma_size) {
|
|
pr_warn_once("HugeTLB: hugetlb_cma is enabled, skip boot time allocation\n");
|
|
return;
|
|
}
|
|
|
|
/* do node specific alloc */
|
|
for_each_online_node(i) {
|
|
if (h->max_huge_pages_node[i] > 0) {
|
|
hugetlb_hstate_alloc_pages_onenode(h, i);
|
|
node_specific_alloc = true;
|
|
}
|
|
}
|
|
|
|
if (node_specific_alloc)
|
|
return;
|
|
|
|
/* below will do all node balanced alloc */
|
|
if (!hstate_is_gigantic(h)) {
|
|
/*
|
|
* Bit mask controlling how hard we retry per-node allocations.
|
|
* Ignore errors as lower level routines can deal with
|
|
* node_alloc_noretry == NULL. If this kmalloc fails at boot
|
|
* time, we are likely in bigger trouble.
|
|
*/
|
|
node_alloc_noretry = kmalloc(sizeof(*node_alloc_noretry),
|
|
GFP_KERNEL);
|
|
} else {
|
|
/* allocations done at boot time */
|
|
node_alloc_noretry = NULL;
|
|
}
|
|
|
|
/* bit mask controlling how hard we retry per-node allocations */
|
|
if (node_alloc_noretry)
|
|
nodes_clear(*node_alloc_noretry);
|
|
|
|
for (i = 0; i < h->max_huge_pages; ++i) {
|
|
if (hstate_is_gigantic(h)) {
|
|
if (!alloc_bootmem_huge_page(h, NUMA_NO_NODE))
|
|
break;
|
|
} else if (!alloc_pool_huge_page(h,
|
|
&node_states[N_MEMORY],
|
|
node_alloc_noretry))
|
|
break;
|
|
cond_resched();
|
|
}
|
|
if (i < h->max_huge_pages) {
|
|
char buf[32];
|
|
|
|
string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32);
|
|
pr_warn("HugeTLB: allocating %lu of page size %s failed. Only allocated %lu hugepages.\n",
|
|
h->max_huge_pages, buf, i);
|
|
h->max_huge_pages = i;
|
|
}
|
|
kfree(node_alloc_noretry);
|
|
}
|
|
|
|
static void __init hugetlb_init_hstates(void)
|
|
{
|
|
struct hstate *h, *h2;
|
|
|
|
for_each_hstate(h) {
|
|
if (minimum_order > huge_page_order(h))
|
|
minimum_order = huge_page_order(h);
|
|
|
|
/* oversize hugepages were init'ed in early boot */
|
|
if (!hstate_is_gigantic(h))
|
|
hugetlb_hstate_alloc_pages(h);
|
|
|
|
/*
|
|
* Set demote order for each hstate. Note that
|
|
* h->demote_order is initially 0.
|
|
* - We can not demote gigantic pages if runtime freeing
|
|
* is not supported, so skip this.
|
|
* - If CMA allocation is possible, we can not demote
|
|
* HUGETLB_PAGE_ORDER or smaller size pages.
|
|
*/
|
|
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
|
|
continue;
|
|
if (hugetlb_cma_size && h->order <= HUGETLB_PAGE_ORDER)
|
|
continue;
|
|
for_each_hstate(h2) {
|
|
if (h2 == h)
|
|
continue;
|
|
if (h2->order < h->order &&
|
|
h2->order > h->demote_order)
|
|
h->demote_order = h2->order;
|
|
}
|
|
}
|
|
VM_BUG_ON(minimum_order == UINT_MAX);
|
|
}
|
|
|
|
static void __init report_hugepages(void)
|
|
{
|
|
struct hstate *h;
|
|
|
|
for_each_hstate(h) {
|
|
char buf[32];
|
|
|
|
string_get_size(huge_page_size(h), 1, STRING_UNITS_2, buf, 32);
|
|
pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n",
|
|
buf, h->free_huge_pages);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
static void try_to_free_low(struct hstate *h, unsigned long count,
|
|
nodemask_t *nodes_allowed)
|
|
{
|
|
int i;
|
|
LIST_HEAD(page_list);
|
|
|
|
lockdep_assert_held(&hugetlb_lock);
|
|
if (hstate_is_gigantic(h))
|
|
return;
|
|
|
|
/*
|
|
* Collect pages to be freed on a list, and free after dropping lock
|
|
*/
|
|
for_each_node_mask(i, *nodes_allowed) {
|
|
struct page *page, *next;
|
|
struct list_head *freel = &h->hugepage_freelists[i];
|
|
list_for_each_entry_safe(page, next, freel, lru) {
|
|
if (count >= h->nr_huge_pages)
|
|
goto out;
|
|
if (PageHighMem(page))
|
|
continue;
|
|
remove_hugetlb_page(h, page, false);
|
|
list_add(&page->lru, &page_list);
|
|
}
|
|
}
|
|
|
|
out:
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
update_and_free_pages_bulk(h, &page_list);
|
|
spin_lock_irq(&hugetlb_lock);
|
|
}
|
|
#else
|
|
static inline void try_to_free_low(struct hstate *h, unsigned long count,
|
|
nodemask_t *nodes_allowed)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Increment or decrement surplus_huge_pages. Keep node-specific counters
|
|
* balanced by operating on them in a round-robin fashion.
|
|
* Returns 1 if an adjustment was made.
|
|
*/
|
|
static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed,
|
|
int delta)
|
|
{
|
|
int nr_nodes, node;
|
|
|
|
lockdep_assert_held(&hugetlb_lock);
|
|
VM_BUG_ON(delta != -1 && delta != 1);
|
|
|
|
if (delta < 0) {
|
|
for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
|
|
if (h->surplus_huge_pages_node[node])
|
|
goto found;
|
|
}
|
|
} else {
|
|
for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) {
|
|
if (h->surplus_huge_pages_node[node] <
|
|
h->nr_huge_pages_node[node])
|
|
goto found;
|
|
}
|
|
}
|
|
return 0;
|
|
|
|
found:
|
|
h->surplus_huge_pages += delta;
|
|
h->surplus_huge_pages_node[node] += delta;
|
|
return 1;
|
|
}
|
|
|
|
#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
|
|
static int set_max_huge_pages(struct hstate *h, unsigned long count, int nid,
|
|
nodemask_t *nodes_allowed)
|
|
{
|
|
unsigned long min_count, ret;
|
|
struct page *page;
|
|
LIST_HEAD(page_list);
|
|
NODEMASK_ALLOC(nodemask_t, node_alloc_noretry, GFP_KERNEL);
|
|
|
|
/*
|
|
* Bit mask controlling how hard we retry per-node allocations.
|
|
* If we can not allocate the bit mask, do not attempt to allocate
|
|
* the requested huge pages.
|
|
*/
|
|
if (node_alloc_noretry)
|
|
nodes_clear(*node_alloc_noretry);
|
|
else
|
|
return -ENOMEM;
|
|
|
|
/*
|
|
* resize_lock mutex prevents concurrent adjustments to number of
|
|
* pages in hstate via the proc/sysfs interfaces.
|
|
*/
|
|
mutex_lock(&h->resize_lock);
|
|
flush_free_hpage_work(h);
|
|
spin_lock_irq(&hugetlb_lock);
|
|
|
|
/*
|
|
* Check for a node specific request.
|
|
* Changing node specific huge page count may require a corresponding
|
|
* change to the global count. In any case, the passed node mask
|
|
* (nodes_allowed) will restrict alloc/free to the specified node.
|
|
*/
|
|
if (nid != NUMA_NO_NODE) {
|
|
unsigned long old_count = count;
|
|
|
|
count += h->nr_huge_pages - h->nr_huge_pages_node[nid];
|
|
/*
|
|
* User may have specified a large count value which caused the
|
|
* above calculation to overflow. In this case, they wanted
|
|
* to allocate as many huge pages as possible. Set count to
|
|
* largest possible value to align with their intention.
|
|
*/
|
|
if (count < old_count)
|
|
count = ULONG_MAX;
|
|
}
|
|
|
|
/*
|
|
* Gigantic pages runtime allocation depend on the capability for large
|
|
* page range allocation.
|
|
* If the system does not provide this feature, return an error when
|
|
* the user tries to allocate gigantic pages but let the user free the
|
|
* boottime allocated gigantic pages.
|
|
*/
|
|
if (hstate_is_gigantic(h) && !IS_ENABLED(CONFIG_CONTIG_ALLOC)) {
|
|
if (count > persistent_huge_pages(h)) {
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
mutex_unlock(&h->resize_lock);
|
|
NODEMASK_FREE(node_alloc_noretry);
|
|
return -EINVAL;
|
|
}
|
|
/* Fall through to decrease pool */
|
|
}
|
|
|
|
/*
|
|
* Increase the pool size
|
|
* First take pages out of surplus state. Then make up the
|
|
* remaining difference by allocating fresh huge pages.
|
|
*
|
|
* We might race with alloc_surplus_huge_page() here and be unable
|
|
* to convert a surplus huge page to a normal huge page. That is
|
|
* not critical, though, it just means the overall size of the
|
|
* pool might be one hugepage larger than it needs to be, but
|
|
* within all the constraints specified by the sysctls.
|
|
*/
|
|
while (h->surplus_huge_pages && count > persistent_huge_pages(h)) {
|
|
if (!adjust_pool_surplus(h, nodes_allowed, -1))
|
|
break;
|
|
}
|
|
|
|
while (count > persistent_huge_pages(h)) {
|
|
/*
|
|
* If this allocation races such that we no longer need the
|
|
* page, free_huge_page will handle it by freeing the page
|
|
* and reducing the surplus.
|
|
*/
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
|
|
/* yield cpu to avoid soft lockup */
|
|
cond_resched();
|
|
|
|
ret = alloc_pool_huge_page(h, nodes_allowed,
|
|
node_alloc_noretry);
|
|
spin_lock_irq(&hugetlb_lock);
|
|
if (!ret)
|
|
goto out;
|
|
|
|
/* Bail for signals. Probably ctrl-c from user */
|
|
if (signal_pending(current))
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Decrease the pool size
|
|
* First return free pages to the buddy allocator (being careful
|
|
* to keep enough around to satisfy reservations). Then place
|
|
* pages into surplus state as needed so the pool will shrink
|
|
* to the desired size as pages become free.
|
|
*
|
|
* By placing pages into the surplus state independent of the
|
|
* overcommit value, we are allowing the surplus pool size to
|
|
* exceed overcommit. There are few sane options here. Since
|
|
* alloc_surplus_huge_page() is checking the global counter,
|
|
* though, we'll note that we're not allowed to exceed surplus
|
|
* and won't grow the pool anywhere else. Not until one of the
|
|
* sysctls are changed, or the surplus pages go out of use.
|
|
*/
|
|
min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages;
|
|
min_count = max(count, min_count);
|
|
try_to_free_low(h, min_count, nodes_allowed);
|
|
|
|
/*
|
|
* Collect pages to be removed on list without dropping lock
|
|
*/
|
|
while (min_count < persistent_huge_pages(h)) {
|
|
page = remove_pool_huge_page(h, nodes_allowed, 0);
|
|
if (!page)
|
|
break;
|
|
|
|
list_add(&page->lru, &page_list);
|
|
}
|
|
/* free the pages after dropping lock */
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
update_and_free_pages_bulk(h, &page_list);
|
|
flush_free_hpage_work(h);
|
|
spin_lock_irq(&hugetlb_lock);
|
|
|
|
while (count < persistent_huge_pages(h)) {
|
|
if (!adjust_pool_surplus(h, nodes_allowed, 1))
|
|
break;
|
|
}
|
|
out:
|
|
h->max_huge_pages = persistent_huge_pages(h);
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
mutex_unlock(&h->resize_lock);
|
|
|
|
NODEMASK_FREE(node_alloc_noretry);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int demote_free_huge_page(struct hstate *h, struct page *page)
|
|
{
|
|
int i, nid = page_to_nid(page);
|
|
struct hstate *target_hstate;
|
|
int rc = 0;
|
|
|
|
target_hstate = size_to_hstate(PAGE_SIZE << h->demote_order);
|
|
|
|
remove_hugetlb_page_for_demote(h, page, false);
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
|
|
rc = hugetlb_vmemmap_alloc(h, page);
|
|
if (rc) {
|
|
/* Allocation of vmemmmap failed, we can not demote page */
|
|
spin_lock_irq(&hugetlb_lock);
|
|
set_page_refcounted(page);
|
|
add_hugetlb_page(h, page, false);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Use destroy_compound_hugetlb_page_for_demote for all huge page
|
|
* sizes as it will not ref count pages.
|
|
*/
|
|
destroy_compound_hugetlb_page_for_demote(page, huge_page_order(h));
|
|
|
|
/*
|
|
* Taking target hstate mutex synchronizes with set_max_huge_pages.
|
|
* Without the mutex, pages added to target hstate could be marked
|
|
* as surplus.
|
|
*
|
|
* Note that we already hold h->resize_lock. To prevent deadlock,
|
|
* use the convention of always taking larger size hstate mutex first.
|
|
*/
|
|
mutex_lock(&target_hstate->resize_lock);
|
|
for (i = 0; i < pages_per_huge_page(h);
|
|
i += pages_per_huge_page(target_hstate)) {
|
|
if (hstate_is_gigantic(target_hstate))
|
|
prep_compound_gigantic_page_for_demote(page + i,
|
|
target_hstate->order);
|
|
else
|
|
prep_compound_page(page + i, target_hstate->order);
|
|
set_page_private(page + i, 0);
|
|
set_page_refcounted(page + i);
|
|
prep_new_huge_page(target_hstate, page + i, nid);
|
|
put_page(page + i);
|
|
}
|
|
mutex_unlock(&target_hstate->resize_lock);
|
|
|
|
spin_lock_irq(&hugetlb_lock);
|
|
|
|
/*
|
|
* Not absolutely necessary, but for consistency update max_huge_pages
|
|
* based on pool changes for the demoted page.
|
|
*/
|
|
h->max_huge_pages--;
|
|
target_hstate->max_huge_pages += pages_per_huge_page(h);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static int demote_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed)
|
|
__must_hold(&hugetlb_lock)
|
|
{
|
|
int nr_nodes, node;
|
|
struct page *page;
|
|
|
|
lockdep_assert_held(&hugetlb_lock);
|
|
|
|
/* We should never get here if no demote order */
|
|
if (!h->demote_order) {
|
|
pr_warn("HugeTLB: NULL demote order passed to demote_pool_huge_page.\n");
|
|
return -EINVAL; /* internal error */
|
|
}
|
|
|
|
for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) {
|
|
list_for_each_entry(page, &h->hugepage_freelists[node], lru) {
|
|
if (PageHWPoison(page))
|
|
continue;
|
|
|
|
return demote_free_huge_page(h, page);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Only way to get here is if all pages on free lists are poisoned.
|
|
* Return -EBUSY so that caller will not retry.
|
|
*/
|
|
return -EBUSY;
|
|
}
|
|
|
|
#define HSTATE_ATTR_RO(_name) \
|
|
static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
|
|
|
|
#define HSTATE_ATTR_WO(_name) \
|
|
static struct kobj_attribute _name##_attr = __ATTR_WO(_name)
|
|
|
|
#define HSTATE_ATTR(_name) \
|
|
static struct kobj_attribute _name##_attr = __ATTR_RW(_name)
|
|
|
|
static struct kobject *hugepages_kobj;
|
|
static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
|
|
|
|
static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp);
|
|
|
|
static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < HUGE_MAX_HSTATE; i++)
|
|
if (hstate_kobjs[i] == kobj) {
|
|
if (nidp)
|
|
*nidp = NUMA_NO_NODE;
|
|
return &hstates[i];
|
|
}
|
|
|
|
return kobj_to_node_hstate(kobj, nidp);
|
|
}
|
|
|
|
static ssize_t nr_hugepages_show_common(struct kobject *kobj,
|
|
struct kobj_attribute *attr, char *buf)
|
|
{
|
|
struct hstate *h;
|
|
unsigned long nr_huge_pages;
|
|
int nid;
|
|
|
|
h = kobj_to_hstate(kobj, &nid);
|
|
if (nid == NUMA_NO_NODE)
|
|
nr_huge_pages = h->nr_huge_pages;
|
|
else
|
|
nr_huge_pages = h->nr_huge_pages_node[nid];
|
|
|
|
return sysfs_emit(buf, "%lu\n", nr_huge_pages);
|
|
}
|
|
|
|
static ssize_t __nr_hugepages_store_common(bool obey_mempolicy,
|
|
struct hstate *h, int nid,
|
|
unsigned long count, size_t len)
|
|
{
|
|
int err;
|
|
nodemask_t nodes_allowed, *n_mask;
|
|
|
|
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
|
|
return -EINVAL;
|
|
|
|
if (nid == NUMA_NO_NODE) {
|
|
/*
|
|
* global hstate attribute
|
|
*/
|
|
if (!(obey_mempolicy &&
|
|
init_nodemask_of_mempolicy(&nodes_allowed)))
|
|
n_mask = &node_states[N_MEMORY];
|
|
else
|
|
n_mask = &nodes_allowed;
|
|
} else {
|
|
/*
|
|
* Node specific request. count adjustment happens in
|
|
* set_max_huge_pages() after acquiring hugetlb_lock.
|
|
*/
|
|
init_nodemask_of_node(&nodes_allowed, nid);
|
|
n_mask = &nodes_allowed;
|
|
}
|
|
|
|
err = set_max_huge_pages(h, count, nid, n_mask);
|
|
|
|
return err ? err : len;
|
|
}
|
|
|
|
static ssize_t nr_hugepages_store_common(bool obey_mempolicy,
|
|
struct kobject *kobj, const char *buf,
|
|
size_t len)
|
|
{
|
|
struct hstate *h;
|
|
unsigned long count;
|
|
int nid;
|
|
int err;
|
|
|
|
err = kstrtoul(buf, 10, &count);
|
|
if (err)
|
|
return err;
|
|
|
|
h = kobj_to_hstate(kobj, &nid);
|
|
return __nr_hugepages_store_common(obey_mempolicy, h, nid, count, len);
|
|
}
|
|
|
|
static ssize_t nr_hugepages_show(struct kobject *kobj,
|
|
struct kobj_attribute *attr, char *buf)
|
|
{
|
|
return nr_hugepages_show_common(kobj, attr, buf);
|
|
}
|
|
|
|
static ssize_t nr_hugepages_store(struct kobject *kobj,
|
|
struct kobj_attribute *attr, const char *buf, size_t len)
|
|
{
|
|
return nr_hugepages_store_common(false, kobj, buf, len);
|
|
}
|
|
HSTATE_ATTR(nr_hugepages);
|
|
|
|
#ifdef CONFIG_NUMA
|
|
|
|
/*
|
|
* hstate attribute for optionally mempolicy-based constraint on persistent
|
|
* huge page alloc/free.
|
|
*/
|
|
static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj,
|
|
struct kobj_attribute *attr,
|
|
char *buf)
|
|
{
|
|
return nr_hugepages_show_common(kobj, attr, buf);
|
|
}
|
|
|
|
static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj,
|
|
struct kobj_attribute *attr, const char *buf, size_t len)
|
|
{
|
|
return nr_hugepages_store_common(true, kobj, buf, len);
|
|
}
|
|
HSTATE_ATTR(nr_hugepages_mempolicy);
|
|
#endif
|
|
|
|
|
|
static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
|
|
struct kobj_attribute *attr, char *buf)
|
|
{
|
|
struct hstate *h = kobj_to_hstate(kobj, NULL);
|
|
return sysfs_emit(buf, "%lu\n", h->nr_overcommit_huge_pages);
|
|
}
|
|
|
|
static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
|
|
struct kobj_attribute *attr, const char *buf, size_t count)
|
|
{
|
|
int err;
|
|
unsigned long input;
|
|
struct hstate *h = kobj_to_hstate(kobj, NULL);
|
|
|
|
if (hstate_is_gigantic(h))
|
|
return -EINVAL;
|
|
|
|
err = kstrtoul(buf, 10, &input);
|
|
if (err)
|
|
return err;
|
|
|
|
spin_lock_irq(&hugetlb_lock);
|
|
h->nr_overcommit_huge_pages = input;
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
|
|
return count;
|
|
}
|
|
HSTATE_ATTR(nr_overcommit_hugepages);
|
|
|
|
static ssize_t free_hugepages_show(struct kobject *kobj,
|
|
struct kobj_attribute *attr, char *buf)
|
|
{
|
|
struct hstate *h;
|
|
unsigned long free_huge_pages;
|
|
int nid;
|
|
|
|
h = kobj_to_hstate(kobj, &nid);
|
|
if (nid == NUMA_NO_NODE)
|
|
free_huge_pages = h->free_huge_pages;
|
|
else
|
|
free_huge_pages = h->free_huge_pages_node[nid];
|
|
|
|
return sysfs_emit(buf, "%lu\n", free_huge_pages);
|
|
}
|
|
HSTATE_ATTR_RO(free_hugepages);
|
|
|
|
static ssize_t resv_hugepages_show(struct kobject *kobj,
|
|
struct kobj_attribute *attr, char *buf)
|
|
{
|
|
struct hstate *h = kobj_to_hstate(kobj, NULL);
|
|
return sysfs_emit(buf, "%lu\n", h->resv_huge_pages);
|
|
}
|
|
HSTATE_ATTR_RO(resv_hugepages);
|
|
|
|
static ssize_t surplus_hugepages_show(struct kobject *kobj,
|
|
struct kobj_attribute *attr, char *buf)
|
|
{
|
|
struct hstate *h;
|
|
unsigned long surplus_huge_pages;
|
|
int nid;
|
|
|
|
h = kobj_to_hstate(kobj, &nid);
|
|
if (nid == NUMA_NO_NODE)
|
|
surplus_huge_pages = h->surplus_huge_pages;
|
|
else
|
|
surplus_huge_pages = h->surplus_huge_pages_node[nid];
|
|
|
|
return sysfs_emit(buf, "%lu\n", surplus_huge_pages);
|
|
}
|
|
HSTATE_ATTR_RO(surplus_hugepages);
|
|
|
|
static ssize_t demote_store(struct kobject *kobj,
|
|
struct kobj_attribute *attr, const char *buf, size_t len)
|
|
{
|
|
unsigned long nr_demote;
|
|
unsigned long nr_available;
|
|
nodemask_t nodes_allowed, *n_mask;
|
|
struct hstate *h;
|
|
int err = 0;
|
|
int nid;
|
|
|
|
err = kstrtoul(buf, 10, &nr_demote);
|
|
if (err)
|
|
return err;
|
|
h = kobj_to_hstate(kobj, &nid);
|
|
|
|
if (nid != NUMA_NO_NODE) {
|
|
init_nodemask_of_node(&nodes_allowed, nid);
|
|
n_mask = &nodes_allowed;
|
|
} else {
|
|
n_mask = &node_states[N_MEMORY];
|
|
}
|
|
|
|
/* Synchronize with other sysfs operations modifying huge pages */
|
|
mutex_lock(&h->resize_lock);
|
|
spin_lock_irq(&hugetlb_lock);
|
|
|
|
while (nr_demote) {
|
|
/*
|
|
* Check for available pages to demote each time thorough the
|
|
* loop as demote_pool_huge_page will drop hugetlb_lock.
|
|
*/
|
|
if (nid != NUMA_NO_NODE)
|
|
nr_available = h->free_huge_pages_node[nid];
|
|
else
|
|
nr_available = h->free_huge_pages;
|
|
nr_available -= h->resv_huge_pages;
|
|
if (!nr_available)
|
|
break;
|
|
|
|
err = demote_pool_huge_page(h, n_mask);
|
|
if (err)
|
|
break;
|
|
|
|
nr_demote--;
|
|
}
|
|
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
mutex_unlock(&h->resize_lock);
|
|
|
|
if (err)
|
|
return err;
|
|
return len;
|
|
}
|
|
HSTATE_ATTR_WO(demote);
|
|
|
|
static ssize_t demote_size_show(struct kobject *kobj,
|
|
struct kobj_attribute *attr, char *buf)
|
|
{
|
|
int nid;
|
|
struct hstate *h = kobj_to_hstate(kobj, &nid);
|
|
unsigned long demote_size = (PAGE_SIZE << h->demote_order) / SZ_1K;
|
|
|
|
return sysfs_emit(buf, "%lukB\n", demote_size);
|
|
}
|
|
|
|
static ssize_t demote_size_store(struct kobject *kobj,
|
|
struct kobj_attribute *attr,
|
|
const char *buf, size_t count)
|
|
{
|
|
struct hstate *h, *demote_hstate;
|
|
unsigned long demote_size;
|
|
unsigned int demote_order;
|
|
int nid;
|
|
|
|
demote_size = (unsigned long)memparse(buf, NULL);
|
|
|
|
demote_hstate = size_to_hstate(demote_size);
|
|
if (!demote_hstate)
|
|
return -EINVAL;
|
|
demote_order = demote_hstate->order;
|
|
if (demote_order < HUGETLB_PAGE_ORDER)
|
|
return -EINVAL;
|
|
|
|
/* demote order must be smaller than hstate order */
|
|
h = kobj_to_hstate(kobj, &nid);
|
|
if (demote_order >= h->order)
|
|
return -EINVAL;
|
|
|
|
/* resize_lock synchronizes access to demote size and writes */
|
|
mutex_lock(&h->resize_lock);
|
|
h->demote_order = demote_order;
|
|
mutex_unlock(&h->resize_lock);
|
|
|
|
return count;
|
|
}
|
|
HSTATE_ATTR(demote_size);
|
|
|
|
static struct attribute *hstate_attrs[] = {
|
|
&nr_hugepages_attr.attr,
|
|
&nr_overcommit_hugepages_attr.attr,
|
|
&free_hugepages_attr.attr,
|
|
&resv_hugepages_attr.attr,
|
|
&surplus_hugepages_attr.attr,
|
|
#ifdef CONFIG_NUMA
|
|
&nr_hugepages_mempolicy_attr.attr,
|
|
#endif
|
|
NULL,
|
|
};
|
|
|
|
static const struct attribute_group hstate_attr_group = {
|
|
.attrs = hstate_attrs,
|
|
};
|
|
|
|
static struct attribute *hstate_demote_attrs[] = {
|
|
&demote_size_attr.attr,
|
|
&demote_attr.attr,
|
|
NULL,
|
|
};
|
|
|
|
static const struct attribute_group hstate_demote_attr_group = {
|
|
.attrs = hstate_demote_attrs,
|
|
};
|
|
|
|
static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
|
|
struct kobject **hstate_kobjs,
|
|
const struct attribute_group *hstate_attr_group)
|
|
{
|
|
int retval;
|
|
int hi = hstate_index(h);
|
|
|
|
hstate_kobjs[hi] = kobject_create_and_add(h->name, parent);
|
|
if (!hstate_kobjs[hi])
|
|
return -ENOMEM;
|
|
|
|
retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group);
|
|
if (retval) {
|
|
kobject_put(hstate_kobjs[hi]);
|
|
hstate_kobjs[hi] = NULL;
|
|
}
|
|
|
|
if (h->demote_order) {
|
|
if (sysfs_create_group(hstate_kobjs[hi],
|
|
&hstate_demote_attr_group))
|
|
pr_warn("HugeTLB unable to create demote interfaces for %s\n", h->name);
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
static void __init hugetlb_sysfs_init(void)
|
|
{
|
|
struct hstate *h;
|
|
int err;
|
|
|
|
hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj);
|
|
if (!hugepages_kobj)
|
|
return;
|
|
|
|
for_each_hstate(h) {
|
|
err = hugetlb_sysfs_add_hstate(h, hugepages_kobj,
|
|
hstate_kobjs, &hstate_attr_group);
|
|
if (err)
|
|
pr_err("HugeTLB: Unable to add hstate %s", h->name);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
|
|
/*
|
|
* node_hstate/s - associate per node hstate attributes, via their kobjects,
|
|
* with node devices in node_devices[] using a parallel array. The array
|
|
* index of a node device or _hstate == node id.
|
|
* This is here to avoid any static dependency of the node device driver, in
|
|
* the base kernel, on the hugetlb module.
|
|
*/
|
|
struct node_hstate {
|
|
struct kobject *hugepages_kobj;
|
|
struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
|
|
};
|
|
static struct node_hstate node_hstates[MAX_NUMNODES];
|
|
|
|
/*
|
|
* A subset of global hstate attributes for node devices
|
|
*/
|
|
static struct attribute *per_node_hstate_attrs[] = {
|
|
&nr_hugepages_attr.attr,
|
|
&free_hugepages_attr.attr,
|
|
&surplus_hugepages_attr.attr,
|
|
NULL,
|
|
};
|
|
|
|
static const struct attribute_group per_node_hstate_attr_group = {
|
|
.attrs = per_node_hstate_attrs,
|
|
};
|
|
|
|
/*
|
|
* kobj_to_node_hstate - lookup global hstate for node device hstate attr kobj.
|
|
* Returns node id via non-NULL nidp.
|
|
*/
|
|
static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
|
|
{
|
|
int nid;
|
|
|
|
for (nid = 0; nid < nr_node_ids; nid++) {
|
|
struct node_hstate *nhs = &node_hstates[nid];
|
|
int i;
|
|
for (i = 0; i < HUGE_MAX_HSTATE; i++)
|
|
if (nhs->hstate_kobjs[i] == kobj) {
|
|
if (nidp)
|
|
*nidp = nid;
|
|
return &hstates[i];
|
|
}
|
|
}
|
|
|
|
BUG();
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Unregister hstate attributes from a single node device.
|
|
* No-op if no hstate attributes attached.
|
|
*/
|
|
static void hugetlb_unregister_node(struct node *node)
|
|
{
|
|
struct hstate *h;
|
|
struct node_hstate *nhs = &node_hstates[node->dev.id];
|
|
|
|
if (!nhs->hugepages_kobj)
|
|
return; /* no hstate attributes */
|
|
|
|
for_each_hstate(h) {
|
|
int idx = hstate_index(h);
|
|
if (nhs->hstate_kobjs[idx]) {
|
|
kobject_put(nhs->hstate_kobjs[idx]);
|
|
nhs->hstate_kobjs[idx] = NULL;
|
|
}
|
|
}
|
|
|
|
kobject_put(nhs->hugepages_kobj);
|
|
nhs->hugepages_kobj = NULL;
|
|
}
|
|
|
|
|
|
/*
|
|
* Register hstate attributes for a single node device.
|
|
* No-op if attributes already registered.
|
|
*/
|
|
static void hugetlb_register_node(struct node *node)
|
|
{
|
|
struct hstate *h;
|
|
struct node_hstate *nhs = &node_hstates[node->dev.id];
|
|
int err;
|
|
|
|
if (nhs->hugepages_kobj)
|
|
return; /* already allocated */
|
|
|
|
nhs->hugepages_kobj = kobject_create_and_add("hugepages",
|
|
&node->dev.kobj);
|
|
if (!nhs->hugepages_kobj)
|
|
return;
|
|
|
|
for_each_hstate(h) {
|
|
err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj,
|
|
nhs->hstate_kobjs,
|
|
&per_node_hstate_attr_group);
|
|
if (err) {
|
|
pr_err("HugeTLB: Unable to add hstate %s for node %d\n",
|
|
h->name, node->dev.id);
|
|
hugetlb_unregister_node(node);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* hugetlb init time: register hstate attributes for all registered node
|
|
* devices of nodes that have memory. All on-line nodes should have
|
|
* registered their associated device by this time.
|
|
*/
|
|
static void __init hugetlb_register_all_nodes(void)
|
|
{
|
|
int nid;
|
|
|
|
for_each_node_state(nid, N_MEMORY) {
|
|
struct node *node = node_devices[nid];
|
|
if (node->dev.id == nid)
|
|
hugetlb_register_node(node);
|
|
}
|
|
|
|
/*
|
|
* Let the node device driver know we're here so it can
|
|
* [un]register hstate attributes on node hotplug.
|
|
*/
|
|
register_hugetlbfs_with_node(hugetlb_register_node,
|
|
hugetlb_unregister_node);
|
|
}
|
|
#else /* !CONFIG_NUMA */
|
|
|
|
static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
|
|
{
|
|
BUG();
|
|
if (nidp)
|
|
*nidp = -1;
|
|
return NULL;
|
|
}
|
|
|
|
static void hugetlb_register_all_nodes(void) { }
|
|
|
|
#endif
|
|
|
|
static int __init hugetlb_init(void)
|
|
{
|
|
int i;
|
|
|
|
BUILD_BUG_ON(sizeof_field(struct page, private) * BITS_PER_BYTE <
|
|
__NR_HPAGEFLAGS);
|
|
|
|
if (!hugepages_supported()) {
|
|
if (hugetlb_max_hstate || default_hstate_max_huge_pages)
|
|
pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n");
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Make sure HPAGE_SIZE (HUGETLB_PAGE_ORDER) hstate exists. Some
|
|
* architectures depend on setup being done here.
|
|
*/
|
|
hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
|
|
if (!parsed_default_hugepagesz) {
|
|
/*
|
|
* If we did not parse a default huge page size, set
|
|
* default_hstate_idx to HPAGE_SIZE hstate. And, if the
|
|
* number of huge pages for this default size was implicitly
|
|
* specified, set that here as well.
|
|
* Note that the implicit setting will overwrite an explicit
|
|
* setting. A warning will be printed in this case.
|
|
*/
|
|
default_hstate_idx = hstate_index(size_to_hstate(HPAGE_SIZE));
|
|
if (default_hstate_max_huge_pages) {
|
|
if (default_hstate.max_huge_pages) {
|
|
char buf[32];
|
|
|
|
string_get_size(huge_page_size(&default_hstate),
|
|
1, STRING_UNITS_2, buf, 32);
|
|
pr_warn("HugeTLB: Ignoring hugepages=%lu associated with %s page size\n",
|
|
default_hstate.max_huge_pages, buf);
|
|
pr_warn("HugeTLB: Using hugepages=%lu for number of default huge pages\n",
|
|
default_hstate_max_huge_pages);
|
|
}
|
|
default_hstate.max_huge_pages =
|
|
default_hstate_max_huge_pages;
|
|
|
|
for_each_online_node(i)
|
|
default_hstate.max_huge_pages_node[i] =
|
|
default_hugepages_in_node[i];
|
|
}
|
|
}
|
|
|
|
hugetlb_cma_check();
|
|
hugetlb_init_hstates();
|
|
gather_bootmem_prealloc();
|
|
report_hugepages();
|
|
|
|
hugetlb_sysfs_init();
|
|
hugetlb_register_all_nodes();
|
|
hugetlb_cgroup_file_init();
|
|
|
|
#ifdef CONFIG_SMP
|
|
num_fault_mutexes = roundup_pow_of_two(8 * num_possible_cpus());
|
|
#else
|
|
num_fault_mutexes = 1;
|
|
#endif
|
|
hugetlb_fault_mutex_table =
|
|
kmalloc_array(num_fault_mutexes, sizeof(struct mutex),
|
|
GFP_KERNEL);
|
|
BUG_ON(!hugetlb_fault_mutex_table);
|
|
|
|
for (i = 0; i < num_fault_mutexes; i++)
|
|
mutex_init(&hugetlb_fault_mutex_table[i]);
|
|
return 0;
|
|
}
|
|
subsys_initcall(hugetlb_init);
|
|
|
|
/* Overwritten by architectures with more huge page sizes */
|
|
bool __init __attribute((weak)) arch_hugetlb_valid_size(unsigned long size)
|
|
{
|
|
return size == HPAGE_SIZE;
|
|
}
|
|
|
|
void __init hugetlb_add_hstate(unsigned int order)
|
|
{
|
|
struct hstate *h;
|
|
unsigned long i;
|
|
|
|
if (size_to_hstate(PAGE_SIZE << order)) {
|
|
return;
|
|
}
|
|
BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE);
|
|
BUG_ON(order == 0);
|
|
h = &hstates[hugetlb_max_hstate++];
|
|
mutex_init(&h->resize_lock);
|
|
h->order = order;
|
|
h->mask = ~(huge_page_size(h) - 1);
|
|
for (i = 0; i < MAX_NUMNODES; ++i)
|
|
INIT_LIST_HEAD(&h->hugepage_freelists[i]);
|
|
INIT_LIST_HEAD(&h->hugepage_activelist);
|
|
h->next_nid_to_alloc = first_memory_node;
|
|
h->next_nid_to_free = first_memory_node;
|
|
snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
|
|
huge_page_size(h)/1024);
|
|
hugetlb_vmemmap_init(h);
|
|
|
|
parsed_hstate = h;
|
|
}
|
|
|
|
bool __init __weak hugetlb_node_alloc_supported(void)
|
|
{
|
|
return true;
|
|
}
|
|
|
|
static void __init hugepages_clear_pages_in_node(void)
|
|
{
|
|
if (!hugetlb_max_hstate) {
|
|
default_hstate_max_huge_pages = 0;
|
|
memset(default_hugepages_in_node, 0,
|
|
MAX_NUMNODES * sizeof(unsigned int));
|
|
} else {
|
|
parsed_hstate->max_huge_pages = 0;
|
|
memset(parsed_hstate->max_huge_pages_node, 0,
|
|
MAX_NUMNODES * sizeof(unsigned int));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* hugepages command line processing
|
|
* hugepages normally follows a valid hugepagsz or default_hugepagsz
|
|
* specification. If not, ignore the hugepages value. hugepages can also
|
|
* be the first huge page command line option in which case it implicitly
|
|
* specifies the number of huge pages for the default size.
|
|
*/
|
|
static int __init hugepages_setup(char *s)
|
|
{
|
|
unsigned long *mhp;
|
|
static unsigned long *last_mhp;
|
|
int node = NUMA_NO_NODE;
|
|
int count;
|
|
unsigned long tmp;
|
|
char *p = s;
|
|
|
|
if (!parsed_valid_hugepagesz) {
|
|
pr_warn("HugeTLB: hugepages=%s does not follow a valid hugepagesz, ignoring\n", s);
|
|
parsed_valid_hugepagesz = true;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter
|
|
* yet, so this hugepages= parameter goes to the "default hstate".
|
|
* Otherwise, it goes with the previously parsed hugepagesz or
|
|
* default_hugepagesz.
|
|
*/
|
|
else if (!hugetlb_max_hstate)
|
|
mhp = &default_hstate_max_huge_pages;
|
|
else
|
|
mhp = &parsed_hstate->max_huge_pages;
|
|
|
|
if (mhp == last_mhp) {
|
|
pr_warn("HugeTLB: hugepages= specified twice without interleaving hugepagesz=, ignoring hugepages=%s\n", s);
|
|
return 1;
|
|
}
|
|
|
|
while (*p) {
|
|
count = 0;
|
|
if (sscanf(p, "%lu%n", &tmp, &count) != 1)
|
|
goto invalid;
|
|
/* Parameter is node format */
|
|
if (p[count] == ':') {
|
|
if (!hugetlb_node_alloc_supported()) {
|
|
pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n");
|
|
return 1;
|
|
}
|
|
if (tmp >= MAX_NUMNODES || !node_online(tmp))
|
|
goto invalid;
|
|
node = array_index_nospec(tmp, MAX_NUMNODES);
|
|
p += count + 1;
|
|
/* Parse hugepages */
|
|
if (sscanf(p, "%lu%n", &tmp, &count) != 1)
|
|
goto invalid;
|
|
if (!hugetlb_max_hstate)
|
|
default_hugepages_in_node[node] = tmp;
|
|
else
|
|
parsed_hstate->max_huge_pages_node[node] = tmp;
|
|
*mhp += tmp;
|
|
/* Go to parse next node*/
|
|
if (p[count] == ',')
|
|
p += count + 1;
|
|
else
|
|
break;
|
|
} else {
|
|
if (p != s)
|
|
goto invalid;
|
|
*mhp = tmp;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Global state is always initialized later in hugetlb_init.
|
|
* But we need to allocate gigantic hstates here early to still
|
|
* use the bootmem allocator.
|
|
*/
|
|
if (hugetlb_max_hstate && hstate_is_gigantic(parsed_hstate))
|
|
hugetlb_hstate_alloc_pages(parsed_hstate);
|
|
|
|
last_mhp = mhp;
|
|
|
|
return 1;
|
|
|
|
invalid:
|
|
pr_warn("HugeTLB: Invalid hugepages parameter %s\n", p);
|
|
hugepages_clear_pages_in_node();
|
|
return 1;
|
|
}
|
|
__setup("hugepages=", hugepages_setup);
|
|
|
|
/*
|
|
* hugepagesz command line processing
|
|
* A specific huge page size can only be specified once with hugepagesz.
|
|
* hugepagesz is followed by hugepages on the command line. The global
|
|
* variable 'parsed_valid_hugepagesz' is used to determine if prior
|
|
* hugepagesz argument was valid.
|
|
*/
|
|
static int __init hugepagesz_setup(char *s)
|
|
{
|
|
unsigned long size;
|
|
struct hstate *h;
|
|
|
|
parsed_valid_hugepagesz = false;
|
|
size = (unsigned long)memparse(s, NULL);
|
|
|
|
if (!arch_hugetlb_valid_size(size)) {
|
|
pr_err("HugeTLB: unsupported hugepagesz=%s\n", s);
|
|
return 1;
|
|
}
|
|
|
|
h = size_to_hstate(size);
|
|
if (h) {
|
|
/*
|
|
* hstate for this size already exists. This is normally
|
|
* an error, but is allowed if the existing hstate is the
|
|
* default hstate. More specifically, it is only allowed if
|
|
* the number of huge pages for the default hstate was not
|
|
* previously specified.
|
|
*/
|
|
if (!parsed_default_hugepagesz || h != &default_hstate ||
|
|
default_hstate.max_huge_pages) {
|
|
pr_warn("HugeTLB: hugepagesz=%s specified twice, ignoring\n", s);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* No need to call hugetlb_add_hstate() as hstate already
|
|
* exists. But, do set parsed_hstate so that a following
|
|
* hugepages= parameter will be applied to this hstate.
|
|
*/
|
|
parsed_hstate = h;
|
|
parsed_valid_hugepagesz = true;
|
|
return 1;
|
|
}
|
|
|
|
hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT);
|
|
parsed_valid_hugepagesz = true;
|
|
return 1;
|
|
}
|
|
__setup("hugepagesz=", hugepagesz_setup);
|
|
|
|
/*
|
|
* default_hugepagesz command line input
|
|
* Only one instance of default_hugepagesz allowed on command line.
|
|
*/
|
|
static int __init default_hugepagesz_setup(char *s)
|
|
{
|
|
unsigned long size;
|
|
int i;
|
|
|
|
parsed_valid_hugepagesz = false;
|
|
if (parsed_default_hugepagesz) {
|
|
pr_err("HugeTLB: default_hugepagesz previously specified, ignoring %s\n", s);
|
|
return 1;
|
|
}
|
|
|
|
size = (unsigned long)memparse(s, NULL);
|
|
|
|
if (!arch_hugetlb_valid_size(size)) {
|
|
pr_err("HugeTLB: unsupported default_hugepagesz=%s\n", s);
|
|
return 1;
|
|
}
|
|
|
|
hugetlb_add_hstate(ilog2(size) - PAGE_SHIFT);
|
|
parsed_valid_hugepagesz = true;
|
|
parsed_default_hugepagesz = true;
|
|
default_hstate_idx = hstate_index(size_to_hstate(size));
|
|
|
|
/*
|
|
* The number of default huge pages (for this size) could have been
|
|
* specified as the first hugetlb parameter: hugepages=X. If so,
|
|
* then default_hstate_max_huge_pages is set. If the default huge
|
|
* page size is gigantic (>= MAX_ORDER), then the pages must be
|
|
* allocated here from bootmem allocator.
|
|
*/
|
|
if (default_hstate_max_huge_pages) {
|
|
default_hstate.max_huge_pages = default_hstate_max_huge_pages;
|
|
for_each_online_node(i)
|
|
default_hstate.max_huge_pages_node[i] =
|
|
default_hugepages_in_node[i];
|
|
if (hstate_is_gigantic(&default_hstate))
|
|
hugetlb_hstate_alloc_pages(&default_hstate);
|
|
default_hstate_max_huge_pages = 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
__setup("default_hugepagesz=", default_hugepagesz_setup);
|
|
|
|
static unsigned int allowed_mems_nr(struct hstate *h)
|
|
{
|
|
int node;
|
|
unsigned int nr = 0;
|
|
nodemask_t *mpol_allowed;
|
|
unsigned int *array = h->free_huge_pages_node;
|
|
gfp_t gfp_mask = htlb_alloc_mask(h);
|
|
|
|
mpol_allowed = policy_nodemask_current(gfp_mask);
|
|
|
|
for_each_node_mask(node, cpuset_current_mems_allowed) {
|
|
if (!mpol_allowed || node_isset(node, *mpol_allowed))
|
|
nr += array[node];
|
|
}
|
|
|
|
return nr;
|
|
}
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
static int proc_hugetlb_doulongvec_minmax(struct ctl_table *table, int write,
|
|
void *buffer, size_t *length,
|
|
loff_t *ppos, unsigned long *out)
|
|
{
|
|
struct ctl_table dup_table;
|
|
|
|
/*
|
|
* In order to avoid races with __do_proc_doulongvec_minmax(), we
|
|
* can duplicate the @table and alter the duplicate of it.
|
|
*/
|
|
dup_table = *table;
|
|
dup_table.data = out;
|
|
|
|
return proc_doulongvec_minmax(&dup_table, write, buffer, length, ppos);
|
|
}
|
|
|
|
static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
|
|
struct ctl_table *table, int write,
|
|
void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
struct hstate *h = &default_hstate;
|
|
unsigned long tmp = h->max_huge_pages;
|
|
int ret;
|
|
|
|
if (!hugepages_supported())
|
|
return -EOPNOTSUPP;
|
|
|
|
ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos,
|
|
&tmp);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (write)
|
|
ret = __nr_hugepages_store_common(obey_mempolicy, h,
|
|
NUMA_NO_NODE, tmp, *length);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
int hugetlb_sysctl_handler(struct ctl_table *table, int write,
|
|
void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
|
|
return hugetlb_sysctl_handler_common(false, table, write,
|
|
buffer, length, ppos);
|
|
}
|
|
|
|
#ifdef CONFIG_NUMA
|
|
int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write,
|
|
void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
return hugetlb_sysctl_handler_common(true, table, write,
|
|
buffer, length, ppos);
|
|
}
|
|
#endif /* CONFIG_NUMA */
|
|
|
|
int hugetlb_overcommit_handler(struct ctl_table *table, int write,
|
|
void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
struct hstate *h = &default_hstate;
|
|
unsigned long tmp;
|
|
int ret;
|
|
|
|
if (!hugepages_supported())
|
|
return -EOPNOTSUPP;
|
|
|
|
tmp = h->nr_overcommit_huge_pages;
|
|
|
|
if (write && hstate_is_gigantic(h))
|
|
return -EINVAL;
|
|
|
|
ret = proc_hugetlb_doulongvec_minmax(table, write, buffer, length, ppos,
|
|
&tmp);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (write) {
|
|
spin_lock_irq(&hugetlb_lock);
|
|
h->nr_overcommit_huge_pages = tmp;
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
}
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
#endif /* CONFIG_SYSCTL */
|
|
|
|
void hugetlb_report_meminfo(struct seq_file *m)
|
|
{
|
|
struct hstate *h;
|
|
unsigned long total = 0;
|
|
|
|
if (!hugepages_supported())
|
|
return;
|
|
|
|
for_each_hstate(h) {
|
|
unsigned long count = h->nr_huge_pages;
|
|
|
|
total += huge_page_size(h) * count;
|
|
|
|
if (h == &default_hstate)
|
|
seq_printf(m,
|
|
"HugePages_Total: %5lu\n"
|
|
"HugePages_Free: %5lu\n"
|
|
"HugePages_Rsvd: %5lu\n"
|
|
"HugePages_Surp: %5lu\n"
|
|
"Hugepagesize: %8lu kB\n",
|
|
count,
|
|
h->free_huge_pages,
|
|
h->resv_huge_pages,
|
|
h->surplus_huge_pages,
|
|
huge_page_size(h) / SZ_1K);
|
|
}
|
|
|
|
seq_printf(m, "Hugetlb: %8lu kB\n", total / SZ_1K);
|
|
}
|
|
|
|
int hugetlb_report_node_meminfo(char *buf, int len, int nid)
|
|
{
|
|
struct hstate *h = &default_hstate;
|
|
|
|
if (!hugepages_supported())
|
|
return 0;
|
|
|
|
return sysfs_emit_at(buf, len,
|
|
"Node %d HugePages_Total: %5u\n"
|
|
"Node %d HugePages_Free: %5u\n"
|
|
"Node %d HugePages_Surp: %5u\n",
|
|
nid, h->nr_huge_pages_node[nid],
|
|
nid, h->free_huge_pages_node[nid],
|
|
nid, h->surplus_huge_pages_node[nid]);
|
|
}
|
|
|
|
void hugetlb_show_meminfo(void)
|
|
{
|
|
struct hstate *h;
|
|
int nid;
|
|
|
|
if (!hugepages_supported())
|
|
return;
|
|
|
|
for_each_node_state(nid, N_MEMORY)
|
|
for_each_hstate(h)
|
|
pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n",
|
|
nid,
|
|
h->nr_huge_pages_node[nid],
|
|
h->free_huge_pages_node[nid],
|
|
h->surplus_huge_pages_node[nid],
|
|
huge_page_size(h) / SZ_1K);
|
|
}
|
|
|
|
void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm)
|
|
{
|
|
seq_printf(m, "HugetlbPages:\t%8lu kB\n",
|
|
atomic_long_read(&mm->hugetlb_usage) << (PAGE_SHIFT - 10));
|
|
}
|
|
|
|
/* Return the number pages of memory we physically have, in PAGE_SIZE units. */
|
|
unsigned long hugetlb_total_pages(void)
|
|
{
|
|
struct hstate *h;
|
|
unsigned long nr_total_pages = 0;
|
|
|
|
for_each_hstate(h)
|
|
nr_total_pages += h->nr_huge_pages * pages_per_huge_page(h);
|
|
return nr_total_pages;
|
|
}
|
|
|
|
static int hugetlb_acct_memory(struct hstate *h, long delta)
|
|
{
|
|
int ret = -ENOMEM;
|
|
|
|
if (!delta)
|
|
return 0;
|
|
|
|
spin_lock_irq(&hugetlb_lock);
|
|
/*
|
|
* When cpuset is configured, it breaks the strict hugetlb page
|
|
* reservation as the accounting is done on a global variable. Such
|
|
* reservation is completely rubbish in the presence of cpuset because
|
|
* the reservation is not checked against page availability for the
|
|
* current cpuset. Application can still potentially OOM'ed by kernel
|
|
* with lack of free htlb page in cpuset that the task is in.
|
|
* Attempt to enforce strict accounting with cpuset is almost
|
|
* impossible (or too ugly) because cpuset is too fluid that
|
|
* task or memory node can be dynamically moved between cpusets.
|
|
*
|
|
* The change of semantics for shared hugetlb mapping with cpuset is
|
|
* undesirable. However, in order to preserve some of the semantics,
|
|
* we fall back to check against current free page availability as
|
|
* a best attempt and hopefully to minimize the impact of changing
|
|
* semantics that cpuset has.
|
|
*
|
|
* Apart from cpuset, we also have memory policy mechanism that
|
|
* also determines from which node the kernel will allocate memory
|
|
* in a NUMA system. So similar to cpuset, we also should consider
|
|
* the memory policy of the current task. Similar to the description
|
|
* above.
|
|
*/
|
|
if (delta > 0) {
|
|
if (gather_surplus_pages(h, delta) < 0)
|
|
goto out;
|
|
|
|
if (delta > allowed_mems_nr(h)) {
|
|
return_unused_surplus_pages(h, delta);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
if (delta < 0)
|
|
return_unused_surplus_pages(h, (unsigned long) -delta);
|
|
|
|
out:
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
return ret;
|
|
}
|
|
|
|
static void hugetlb_vm_op_open(struct vm_area_struct *vma)
|
|
{
|
|
struct resv_map *resv = vma_resv_map(vma);
|
|
|
|
/*
|
|
* This new VMA should share its siblings reservation map if present.
|
|
* The VMA will only ever have a valid reservation map pointer where
|
|
* it is being copied for another still existing VMA. As that VMA
|
|
* has a reference to the reservation map it cannot disappear until
|
|
* after this open call completes. It is therefore safe to take a
|
|
* new reference here without additional locking.
|
|
*/
|
|
if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
|
|
resv_map_dup_hugetlb_cgroup_uncharge_info(resv);
|
|
kref_get(&resv->refs);
|
|
}
|
|
}
|
|
|
|
static void hugetlb_vm_op_close(struct vm_area_struct *vma)
|
|
{
|
|
struct hstate *h = hstate_vma(vma);
|
|
struct resv_map *resv = vma_resv_map(vma);
|
|
struct hugepage_subpool *spool = subpool_vma(vma);
|
|
unsigned long reserve, start, end;
|
|
long gbl_reserve;
|
|
|
|
if (!resv || !is_vma_resv_set(vma, HPAGE_RESV_OWNER))
|
|
return;
|
|
|
|
start = vma_hugecache_offset(h, vma, vma->vm_start);
|
|
end = vma_hugecache_offset(h, vma, vma->vm_end);
|
|
|
|
reserve = (end - start) - region_count(resv, start, end);
|
|
hugetlb_cgroup_uncharge_counter(resv, start, end);
|
|
if (reserve) {
|
|
/*
|
|
* Decrement reserve counts. The global reserve count may be
|
|
* adjusted if the subpool has a minimum size.
|
|
*/
|
|
gbl_reserve = hugepage_subpool_put_pages(spool, reserve);
|
|
hugetlb_acct_memory(h, -gbl_reserve);
|
|
}
|
|
|
|
kref_put(&resv->refs, resv_map_release);
|
|
}
|
|
|
|
static int hugetlb_vm_op_split(struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
if (addr & ~(huge_page_mask(hstate_vma(vma))))
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long hugetlb_vm_op_pagesize(struct vm_area_struct *vma)
|
|
{
|
|
return huge_page_size(hstate_vma(vma));
|
|
}
|
|
|
|
/*
|
|
* We cannot handle pagefaults against hugetlb pages at all. They cause
|
|
* handle_mm_fault() to try to instantiate regular-sized pages in the
|
|
* hugepage VMA. do_page_fault() is supposed to trap this, so BUG is we get
|
|
* this far.
|
|
*/
|
|
static vm_fault_t hugetlb_vm_op_fault(struct vm_fault *vmf)
|
|
{
|
|
BUG();
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* When a new function is introduced to vm_operations_struct and added
|
|
* to hugetlb_vm_ops, please consider adding the function to shm_vm_ops.
|
|
* This is because under System V memory model, mappings created via
|
|
* shmget/shmat with "huge page" specified are backed by hugetlbfs files,
|
|
* their original vm_ops are overwritten with shm_vm_ops.
|
|
*/
|
|
const struct vm_operations_struct hugetlb_vm_ops = {
|
|
.fault = hugetlb_vm_op_fault,
|
|
.open = hugetlb_vm_op_open,
|
|
.close = hugetlb_vm_op_close,
|
|
.may_split = hugetlb_vm_op_split,
|
|
.pagesize = hugetlb_vm_op_pagesize,
|
|
};
|
|
|
|
static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
|
|
int writable)
|
|
{
|
|
pte_t entry;
|
|
unsigned int shift = huge_page_shift(hstate_vma(vma));
|
|
|
|
if (writable) {
|
|
entry = huge_pte_mkwrite(huge_pte_mkdirty(mk_huge_pte(page,
|
|
vma->vm_page_prot)));
|
|
} else {
|
|
entry = huge_pte_wrprotect(mk_huge_pte(page,
|
|
vma->vm_page_prot));
|
|
}
|
|
entry = pte_mkyoung(entry);
|
|
entry = arch_make_huge_pte(entry, shift, vma->vm_flags);
|
|
|
|
return entry;
|
|
}
|
|
|
|
static void set_huge_ptep_writable(struct vm_area_struct *vma,
|
|
unsigned long address, pte_t *ptep)
|
|
{
|
|
pte_t entry;
|
|
|
|
entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep)));
|
|
if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1))
|
|
update_mmu_cache(vma, address, ptep);
|
|
}
|
|
|
|
bool is_hugetlb_entry_migration(pte_t pte)
|
|
{
|
|
swp_entry_t swp;
|
|
|
|
if (huge_pte_none(pte) || pte_present(pte))
|
|
return false;
|
|
swp = pte_to_swp_entry(pte);
|
|
if (is_migration_entry(swp))
|
|
return true;
|
|
else
|
|
return false;
|
|
}
|
|
|
|
static bool is_hugetlb_entry_hwpoisoned(pte_t pte)
|
|
{
|
|
swp_entry_t swp;
|
|
|
|
if (huge_pte_none(pte) || pte_present(pte))
|
|
return false;
|
|
swp = pte_to_swp_entry(pte);
|
|
if (is_hwpoison_entry(swp))
|
|
return true;
|
|
else
|
|
return false;
|
|
}
|
|
|
|
static void
|
|
hugetlb_install_page(struct vm_area_struct *vma, pte_t *ptep, unsigned long addr,
|
|
struct page *new_page)
|
|
{
|
|
__SetPageUptodate(new_page);
|
|
hugepage_add_new_anon_rmap(new_page, vma, addr);
|
|
set_huge_pte_at(vma->vm_mm, addr, ptep, make_huge_pte(vma, new_page, 1));
|
|
hugetlb_count_add(pages_per_huge_page(hstate_vma(vma)), vma->vm_mm);
|
|
ClearHPageRestoreReserve(new_page);
|
|
SetHPageMigratable(new_page);
|
|
}
|
|
|
|
int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
|
|
struct vm_area_struct *dst_vma,
|
|
struct vm_area_struct *src_vma)
|
|
{
|
|
pte_t *src_pte, *dst_pte, entry, dst_entry;
|
|
struct page *ptepage;
|
|
unsigned long addr;
|
|
bool cow = is_cow_mapping(src_vma->vm_flags);
|
|
struct hstate *h = hstate_vma(src_vma);
|
|
unsigned long sz = huge_page_size(h);
|
|
unsigned long npages = pages_per_huge_page(h);
|
|
struct address_space *mapping = src_vma->vm_file->f_mapping;
|
|
struct mmu_notifier_range range;
|
|
int ret = 0;
|
|
|
|
if (cow) {
|
|
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, src_vma, src,
|
|
src_vma->vm_start,
|
|
src_vma->vm_end);
|
|
mmu_notifier_invalidate_range_start(&range);
|
|
mmap_assert_write_locked(src);
|
|
raw_write_seqcount_begin(&src->write_protect_seq);
|
|
} else {
|
|
/*
|
|
* For shared mappings i_mmap_rwsem must be held to call
|
|
* huge_pte_alloc, otherwise the returned ptep could go
|
|
* away if part of a shared pmd and another thread calls
|
|
* huge_pmd_unshare.
|
|
*/
|
|
i_mmap_lock_read(mapping);
|
|
}
|
|
|
|
for (addr = src_vma->vm_start; addr < src_vma->vm_end; addr += sz) {
|
|
spinlock_t *src_ptl, *dst_ptl;
|
|
src_pte = huge_pte_offset(src, addr, sz);
|
|
if (!src_pte)
|
|
continue;
|
|
dst_pte = huge_pte_alloc(dst, dst_vma, addr, sz);
|
|
if (!dst_pte) {
|
|
ret = -ENOMEM;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If the pagetables are shared don't copy or take references.
|
|
* dst_pte == src_pte is the common case of src/dest sharing.
|
|
*
|
|
* However, src could have 'unshared' and dst shares with
|
|
* another vma. If dst_pte !none, this implies sharing.
|
|
* Check here before taking page table lock, and once again
|
|
* after taking the lock below.
|
|
*/
|
|
dst_entry = huge_ptep_get(dst_pte);
|
|
if ((dst_pte == src_pte) || !huge_pte_none(dst_entry))
|
|
continue;
|
|
|
|
dst_ptl = huge_pte_lock(h, dst, dst_pte);
|
|
src_ptl = huge_pte_lockptr(h, src, src_pte);
|
|
spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
|
|
entry = huge_ptep_get(src_pte);
|
|
dst_entry = huge_ptep_get(dst_pte);
|
|
again:
|
|
if (huge_pte_none(entry) || !huge_pte_none(dst_entry)) {
|
|
/*
|
|
* Skip if src entry none. Also, skip in the
|
|
* unlikely case dst entry !none as this implies
|
|
* sharing with another vma.
|
|
*/
|
|
;
|
|
} else if (unlikely(is_hugetlb_entry_migration(entry) ||
|
|
is_hugetlb_entry_hwpoisoned(entry))) {
|
|
swp_entry_t swp_entry = pte_to_swp_entry(entry);
|
|
bool uffd_wp = huge_pte_uffd_wp(entry);
|
|
|
|
if (!is_readable_migration_entry(swp_entry) && cow) {
|
|
/*
|
|
* COW mappings require pages in both
|
|
* parent and child to be set to read.
|
|
*/
|
|
swp_entry = make_readable_migration_entry(
|
|
swp_offset(swp_entry));
|
|
entry = swp_entry_to_pte(swp_entry);
|
|
if (userfaultfd_wp(src_vma) && uffd_wp)
|
|
entry = huge_pte_mkuffd_wp(entry);
|
|
set_huge_swap_pte_at(src, addr, src_pte,
|
|
entry, sz);
|
|
}
|
|
if (!userfaultfd_wp(dst_vma) && uffd_wp)
|
|
entry = huge_pte_clear_uffd_wp(entry);
|
|
set_huge_swap_pte_at(dst, addr, dst_pte, entry, sz);
|
|
} else if (unlikely(is_pte_marker(entry))) {
|
|
/*
|
|
* We copy the pte marker only if the dst vma has
|
|
* uffd-wp enabled.
|
|
*/
|
|
if (userfaultfd_wp(dst_vma))
|
|
set_huge_pte_at(dst, addr, dst_pte, entry);
|
|
} else {
|
|
entry = huge_ptep_get(src_pte);
|
|
ptepage = pte_page(entry);
|
|
get_page(ptepage);
|
|
|
|
/*
|
|
* Failing to duplicate the anon rmap is a rare case
|
|
* where we see pinned hugetlb pages while they're
|
|
* prone to COW. We need to do the COW earlier during
|
|
* fork.
|
|
*
|
|
* When pre-allocating the page or copying data, we
|
|
* need to be without the pgtable locks since we could
|
|
* sleep during the process.
|
|
*/
|
|
if (!PageAnon(ptepage)) {
|
|
page_dup_file_rmap(ptepage, true);
|
|
} else if (page_try_dup_anon_rmap(ptepage, true,
|
|
src_vma)) {
|
|
pte_t src_pte_old = entry;
|
|
struct page *new;
|
|
|
|
spin_unlock(src_ptl);
|
|
spin_unlock(dst_ptl);
|
|
/* Do not use reserve as it's private owned */
|
|
new = alloc_huge_page(dst_vma, addr, 1);
|
|
if (IS_ERR(new)) {
|
|
put_page(ptepage);
|
|
ret = PTR_ERR(new);
|
|
break;
|
|
}
|
|
copy_user_huge_page(new, ptepage, addr, dst_vma,
|
|
npages);
|
|
put_page(ptepage);
|
|
|
|
/* Install the new huge page if src pte stable */
|
|
dst_ptl = huge_pte_lock(h, dst, dst_pte);
|
|
src_ptl = huge_pte_lockptr(h, src, src_pte);
|
|
spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
|
|
entry = huge_ptep_get(src_pte);
|
|
if (!pte_same(src_pte_old, entry)) {
|
|
restore_reserve_on_error(h, dst_vma, addr,
|
|
new);
|
|
put_page(new);
|
|
/* dst_entry won't change as in child */
|
|
goto again;
|
|
}
|
|
hugetlb_install_page(dst_vma, dst_pte, addr, new);
|
|
spin_unlock(src_ptl);
|
|
spin_unlock(dst_ptl);
|
|
continue;
|
|
}
|
|
|
|
if (cow) {
|
|
/*
|
|
* No need to notify as we are downgrading page
|
|
* table protection not changing it to point
|
|
* to a new page.
|
|
*
|
|
* See Documentation/vm/mmu_notifier.rst
|
|
*/
|
|
huge_ptep_set_wrprotect(src, addr, src_pte);
|
|
entry = huge_pte_wrprotect(entry);
|
|
}
|
|
|
|
set_huge_pte_at(dst, addr, dst_pte, entry);
|
|
hugetlb_count_add(npages, dst);
|
|
}
|
|
spin_unlock(src_ptl);
|
|
spin_unlock(dst_ptl);
|
|
}
|
|
|
|
if (cow) {
|
|
raw_write_seqcount_end(&src->write_protect_seq);
|
|
mmu_notifier_invalidate_range_end(&range);
|
|
} else {
|
|
i_mmap_unlock_read(mapping);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
|
|
unsigned long new_addr, pte_t *src_pte, pte_t *dst_pte)
|
|
{
|
|
struct hstate *h = hstate_vma(vma);
|
|
struct mm_struct *mm = vma->vm_mm;
|
|
spinlock_t *src_ptl, *dst_ptl;
|
|
pte_t pte;
|
|
|
|
dst_ptl = huge_pte_lock(h, mm, dst_pte);
|
|
src_ptl = huge_pte_lockptr(h, mm, src_pte);
|
|
|
|
/*
|
|
* We don't have to worry about the ordering of src and dst ptlocks
|
|
* because exclusive mmap_sem (or the i_mmap_lock) prevents deadlock.
|
|
*/
|
|
if (src_ptl != dst_ptl)
|
|
spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
|
|
|
|
pte = huge_ptep_get_and_clear(mm, old_addr, src_pte);
|
|
set_huge_pte_at(mm, new_addr, dst_pte, pte);
|
|
|
|
if (src_ptl != dst_ptl)
|
|
spin_unlock(src_ptl);
|
|
spin_unlock(dst_ptl);
|
|
}
|
|
|
|
int move_hugetlb_page_tables(struct vm_area_struct *vma,
|
|
struct vm_area_struct *new_vma,
|
|
unsigned long old_addr, unsigned long new_addr,
|
|
unsigned long len)
|
|
{
|
|
struct hstate *h = hstate_vma(vma);
|
|
struct address_space *mapping = vma->vm_file->f_mapping;
|
|
unsigned long sz = huge_page_size(h);
|
|
struct mm_struct *mm = vma->vm_mm;
|
|
unsigned long old_end = old_addr + len;
|
|
unsigned long old_addr_copy;
|
|
pte_t *src_pte, *dst_pte;
|
|
struct mmu_notifier_range range;
|
|
bool shared_pmd = false;
|
|
|
|
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, old_addr,
|
|
old_end);
|
|
adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end);
|
|
/*
|
|
* In case of shared PMDs, we should cover the maximum possible
|
|
* range.
|
|
*/
|
|
flush_cache_range(vma, range.start, range.end);
|
|
|
|
mmu_notifier_invalidate_range_start(&range);
|
|
/* Prevent race with file truncation */
|
|
i_mmap_lock_write(mapping);
|
|
for (; old_addr < old_end; old_addr += sz, new_addr += sz) {
|
|
src_pte = huge_pte_offset(mm, old_addr, sz);
|
|
if (!src_pte)
|
|
continue;
|
|
if (huge_pte_none(huge_ptep_get(src_pte)))
|
|
continue;
|
|
|
|
/* old_addr arg to huge_pmd_unshare() is a pointer and so the
|
|
* arg may be modified. Pass a copy instead to preserve the
|
|
* value in old_addr.
|
|
*/
|
|
old_addr_copy = old_addr;
|
|
|
|
if (huge_pmd_unshare(mm, vma, &old_addr_copy, src_pte)) {
|
|
shared_pmd = true;
|
|
continue;
|
|
}
|
|
|
|
dst_pte = huge_pte_alloc(mm, new_vma, new_addr, sz);
|
|
if (!dst_pte)
|
|
break;
|
|
|
|
move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte);
|
|
}
|
|
|
|
if (shared_pmd)
|
|
flush_tlb_range(vma, range.start, range.end);
|
|
else
|
|
flush_tlb_range(vma, old_end - len, old_end);
|
|
mmu_notifier_invalidate_range_end(&range);
|
|
i_mmap_unlock_write(mapping);
|
|
|
|
return len + old_addr - old_end;
|
|
}
|
|
|
|
static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
|
|
unsigned long start, unsigned long end,
|
|
struct page *ref_page, zap_flags_t zap_flags)
|
|
{
|
|
struct mm_struct *mm = vma->vm_mm;
|
|
unsigned long address;
|
|
pte_t *ptep;
|
|
pte_t pte;
|
|
spinlock_t *ptl;
|
|
struct page *page;
|
|
struct hstate *h = hstate_vma(vma);
|
|
unsigned long sz = huge_page_size(h);
|
|
struct mmu_notifier_range range;
|
|
bool force_flush = false;
|
|
|
|
WARN_ON(!is_vm_hugetlb_page(vma));
|
|
BUG_ON(start & ~huge_page_mask(h));
|
|
BUG_ON(end & ~huge_page_mask(h));
|
|
|
|
/*
|
|
* This is a hugetlb vma, all the pte entries should point
|
|
* to huge page.
|
|
*/
|
|
tlb_change_page_size(tlb, sz);
|
|
tlb_start_vma(tlb, vma);
|
|
|
|
/*
|
|
* If sharing possible, alert mmu notifiers of worst case.
|
|
*/
|
|
mmu_notifier_range_init(&range, MMU_NOTIFY_UNMAP, 0, vma, mm, start,
|
|
end);
|
|
adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end);
|
|
mmu_notifier_invalidate_range_start(&range);
|
|
address = start;
|
|
for (; address < end; address += sz) {
|
|
ptep = huge_pte_offset(mm, address, sz);
|
|
if (!ptep)
|
|
continue;
|
|
|
|
ptl = huge_pte_lock(h, mm, ptep);
|
|
if (huge_pmd_unshare(mm, vma, &address, ptep)) {
|
|
spin_unlock(ptl);
|
|
tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE);
|
|
force_flush = true;
|
|
continue;
|
|
}
|
|
|
|
pte = huge_ptep_get(ptep);
|
|
if (huge_pte_none(pte)) {
|
|
spin_unlock(ptl);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Migrating hugepage or HWPoisoned hugepage is already
|
|
* unmapped and its refcount is dropped, so just clear pte here.
|
|
*/
|
|
if (unlikely(!pte_present(pte))) {
|
|
/*
|
|
* If the pte was wr-protected by uffd-wp in any of the
|
|
* swap forms, meanwhile the caller does not want to
|
|
* drop the uffd-wp bit in this zap, then replace the
|
|
* pte with a marker.
|
|
*/
|
|
if (pte_swp_uffd_wp_any(pte) &&
|
|
!(zap_flags & ZAP_FLAG_DROP_MARKER))
|
|
set_huge_pte_at(mm, address, ptep,
|
|
make_pte_marker(PTE_MARKER_UFFD_WP));
|
|
else
|
|
huge_pte_clear(mm, address, ptep, sz);
|
|
spin_unlock(ptl);
|
|
continue;
|
|
}
|
|
|
|
page = pte_page(pte);
|
|
/*
|
|
* If a reference page is supplied, it is because a specific
|
|
* page is being unmapped, not a range. Ensure the page we
|
|
* are about to unmap is the actual page of interest.
|
|
*/
|
|
if (ref_page) {
|
|
if (page != ref_page) {
|
|
spin_unlock(ptl);
|
|
continue;
|
|
}
|
|
/*
|
|
* Mark the VMA as having unmapped its page so that
|
|
* future faults in this VMA will fail rather than
|
|
* looking like data was lost
|
|
*/
|
|
set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
|
|
}
|
|
|
|
pte = huge_ptep_get_and_clear(mm, address, ptep);
|
|
tlb_remove_huge_tlb_entry(h, tlb, ptep, address);
|
|
if (huge_pte_dirty(pte))
|
|
set_page_dirty(page);
|
|
/* Leave a uffd-wp pte marker if needed */
|
|
if (huge_pte_uffd_wp(pte) &&
|
|
!(zap_flags & ZAP_FLAG_DROP_MARKER))
|
|
set_huge_pte_at(mm, address, ptep,
|
|
make_pte_marker(PTE_MARKER_UFFD_WP));
|
|
hugetlb_count_sub(pages_per_huge_page(h), mm);
|
|
page_remove_rmap(page, vma, true);
|
|
|
|
spin_unlock(ptl);
|
|
tlb_remove_page_size(tlb, page, huge_page_size(h));
|
|
/*
|
|
* Bail out after unmapping reference page if supplied
|
|
*/
|
|
if (ref_page)
|
|
break;
|
|
}
|
|
mmu_notifier_invalidate_range_end(&range);
|
|
tlb_end_vma(tlb, vma);
|
|
|
|
/*
|
|
* If we unshared PMDs, the TLB flush was not recorded in mmu_gather. We
|
|
* could defer the flush until now, since by holding i_mmap_rwsem we
|
|
* guaranteed that the last refernece would not be dropped. But we must
|
|
* do the flushing before we return, as otherwise i_mmap_rwsem will be
|
|
* dropped and the last reference to the shared PMDs page might be
|
|
* dropped as well.
|
|
*
|
|
* In theory we could defer the freeing of the PMD pages as well, but
|
|
* huge_pmd_unshare() relies on the exact page_count for the PMD page to
|
|
* detect sharing, so we cannot defer the release of the page either.
|
|
* Instead, do flush now.
|
|
*/
|
|
if (force_flush)
|
|
tlb_flush_mmu_tlbonly(tlb);
|
|
}
|
|
|
|
void __unmap_hugepage_range_final(struct mmu_gather *tlb,
|
|
struct vm_area_struct *vma, unsigned long start,
|
|
unsigned long end, struct page *ref_page,
|
|
zap_flags_t zap_flags)
|
|
{
|
|
__unmap_hugepage_range(tlb, vma, start, end, ref_page, zap_flags);
|
|
|
|
/*
|
|
* Clear this flag so that x86's huge_pmd_share page_table_shareable
|
|
* test will fail on a vma being torn down, and not grab a page table
|
|
* on its way out. We're lucky that the flag has such an appropriate
|
|
* name, and can in fact be safely cleared here. We could clear it
|
|
* before the __unmap_hugepage_range above, but all that's necessary
|
|
* is to clear it before releasing the i_mmap_rwsem. This works
|
|
* because in the context this is called, the VMA is about to be
|
|
* destroyed and the i_mmap_rwsem is held.
|
|
*/
|
|
vma->vm_flags &= ~VM_MAYSHARE;
|
|
}
|
|
|
|
void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
|
|
unsigned long end, struct page *ref_page,
|
|
zap_flags_t zap_flags)
|
|
{
|
|
struct mmu_gather tlb;
|
|
|
|
tlb_gather_mmu(&tlb, vma->vm_mm);
|
|
__unmap_hugepage_range(&tlb, vma, start, end, ref_page, zap_flags);
|
|
tlb_finish_mmu(&tlb);
|
|
}
|
|
|
|
/*
|
|
* This is called when the original mapper is failing to COW a MAP_PRIVATE
|
|
* mapping it owns the reserve page for. The intention is to unmap the page
|
|
* from other VMAs and let the children be SIGKILLed if they are faulting the
|
|
* same region.
|
|
*/
|
|
static void unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
|
|
struct page *page, unsigned long address)
|
|
{
|
|
struct hstate *h = hstate_vma(vma);
|
|
struct vm_area_struct *iter_vma;
|
|
struct address_space *mapping;
|
|
pgoff_t pgoff;
|
|
|
|
/*
|
|
* vm_pgoff is in PAGE_SIZE units, hence the different calculation
|
|
* from page cache lookup which is in HPAGE_SIZE units.
|
|
*/
|
|
address = address & huge_page_mask(h);
|
|
pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) +
|
|
vma->vm_pgoff;
|
|
mapping = vma->vm_file->f_mapping;
|
|
|
|
/*
|
|
* Take the mapping lock for the duration of the table walk. As
|
|
* this mapping should be shared between all the VMAs,
|
|
* __unmap_hugepage_range() is called as the lock is already held
|
|
*/
|
|
i_mmap_lock_write(mapping);
|
|
vma_interval_tree_foreach(iter_vma, &mapping->i_mmap, pgoff, pgoff) {
|
|
/* Do not unmap the current VMA */
|
|
if (iter_vma == vma)
|
|
continue;
|
|
|
|
/*
|
|
* Shared VMAs have their own reserves and do not affect
|
|
* MAP_PRIVATE accounting but it is possible that a shared
|
|
* VMA is using the same page so check and skip such VMAs.
|
|
*/
|
|
if (iter_vma->vm_flags & VM_MAYSHARE)
|
|
continue;
|
|
|
|
/*
|
|
* Unmap the page from other VMAs without their own reserves.
|
|
* They get marked to be SIGKILLed if they fault in these
|
|
* areas. This is because a future no-page fault on this VMA
|
|
* could insert a zeroed page instead of the data existing
|
|
* from the time of fork. This would look like data corruption
|
|
*/
|
|
if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
|
|
unmap_hugepage_range(iter_vma, address,
|
|
address + huge_page_size(h), page, 0);
|
|
}
|
|
i_mmap_unlock_write(mapping);
|
|
}
|
|
|
|
/*
|
|
* hugetlb_wp() should be called with page lock of the original hugepage held.
|
|
* Called with hugetlb_fault_mutex_table held and pte_page locked so we
|
|
* cannot race with other handlers or page migration.
|
|
* Keep the pte_same checks anyway to make transition from the mutex easier.
|
|
*/
|
|
static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
|
|
unsigned long address, pte_t *ptep, unsigned int flags,
|
|
struct page *pagecache_page, spinlock_t *ptl)
|
|
{
|
|
const bool unshare = flags & FAULT_FLAG_UNSHARE;
|
|
pte_t pte;
|
|
struct hstate *h = hstate_vma(vma);
|
|
struct page *old_page, *new_page;
|
|
int outside_reserve = 0;
|
|
vm_fault_t ret = 0;
|
|
unsigned long haddr = address & huge_page_mask(h);
|
|
struct mmu_notifier_range range;
|
|
|
|
VM_BUG_ON(unshare && (flags & FOLL_WRITE));
|
|
VM_BUG_ON(!unshare && !(flags & FOLL_WRITE));
|
|
|
|
pte = huge_ptep_get(ptep);
|
|
old_page = pte_page(pte);
|
|
|
|
delayacct_wpcopy_start();
|
|
|
|
retry_avoidcopy:
|
|
/*
|
|
* If no-one else is actually using this page, we're the exclusive
|
|
* owner and can reuse this page.
|
|
*/
|
|
if (page_mapcount(old_page) == 1 && PageAnon(old_page)) {
|
|
if (!PageAnonExclusive(old_page))
|
|
page_move_anon_rmap(old_page, vma);
|
|
if (likely(!unshare))
|
|
set_huge_ptep_writable(vma, haddr, ptep);
|
|
|
|
delayacct_wpcopy_end();
|
|
return 0;
|
|
}
|
|
VM_BUG_ON_PAGE(PageAnon(old_page) && PageAnonExclusive(old_page),
|
|
old_page);
|
|
|
|
/*
|
|
* If the process that created a MAP_PRIVATE mapping is about to
|
|
* perform a COW due to a shared page count, attempt to satisfy
|
|
* the allocation without using the existing reserves. The pagecache
|
|
* page is used to determine if the reserve at this address was
|
|
* consumed or not. If reserves were used, a partial faulted mapping
|
|
* at the time of fork() could consume its reserves on COW instead
|
|
* of the full address range.
|
|
*/
|
|
if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
|
|
old_page != pagecache_page)
|
|
outside_reserve = 1;
|
|
|
|
get_page(old_page);
|
|
|
|
/*
|
|
* Drop page table lock as buddy allocator may be called. It will
|
|
* be acquired again before returning to the caller, as expected.
|
|
*/
|
|
spin_unlock(ptl);
|
|
new_page = alloc_huge_page(vma, haddr, outside_reserve);
|
|
|
|
if (IS_ERR(new_page)) {
|
|
/*
|
|
* If a process owning a MAP_PRIVATE mapping fails to COW,
|
|
* it is due to references held by a child and an insufficient
|
|
* huge page pool. To guarantee the original mappers
|
|
* reliability, unmap the page from child processes. The child
|
|
* may get SIGKILLed if it later faults.
|
|
*/
|
|
if (outside_reserve) {
|
|
struct address_space *mapping = vma->vm_file->f_mapping;
|
|
pgoff_t idx;
|
|
u32 hash;
|
|
|
|
put_page(old_page);
|
|
BUG_ON(huge_pte_none(pte));
|
|
/*
|
|
* Drop hugetlb_fault_mutex and i_mmap_rwsem before
|
|
* unmapping. unmapping needs to hold i_mmap_rwsem
|
|
* in write mode. Dropping i_mmap_rwsem in read mode
|
|
* here is OK as COW mappings do not interact with
|
|
* PMD sharing.
|
|
*
|
|
* Reacquire both after unmap operation.
|
|
*/
|
|
idx = vma_hugecache_offset(h, vma, haddr);
|
|
hash = hugetlb_fault_mutex_hash(mapping, idx);
|
|
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
|
|
i_mmap_unlock_read(mapping);
|
|
|
|
unmap_ref_private(mm, vma, old_page, haddr);
|
|
|
|
i_mmap_lock_read(mapping);
|
|
mutex_lock(&hugetlb_fault_mutex_table[hash]);
|
|
spin_lock(ptl);
|
|
ptep = huge_pte_offset(mm, haddr, huge_page_size(h));
|
|
if (likely(ptep &&
|
|
pte_same(huge_ptep_get(ptep), pte)))
|
|
goto retry_avoidcopy;
|
|
/*
|
|
* race occurs while re-acquiring page table
|
|
* lock, and our job is done.
|
|
*/
|
|
delayacct_wpcopy_end();
|
|
return 0;
|
|
}
|
|
|
|
ret = vmf_error(PTR_ERR(new_page));
|
|
goto out_release_old;
|
|
}
|
|
|
|
/*
|
|
* When the original hugepage is shared one, it does not have
|
|
* anon_vma prepared.
|
|
*/
|
|
if (unlikely(anon_vma_prepare(vma))) {
|
|
ret = VM_FAULT_OOM;
|
|
goto out_release_all;
|
|
}
|
|
|
|
copy_user_huge_page(new_page, old_page, address, vma,
|
|
pages_per_huge_page(h));
|
|
__SetPageUptodate(new_page);
|
|
|
|
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr,
|
|
haddr + huge_page_size(h));
|
|
mmu_notifier_invalidate_range_start(&range);
|
|
|
|
/*
|
|
* Retake the page table lock to check for racing updates
|
|
* before the page tables are altered
|
|
*/
|
|
spin_lock(ptl);
|
|
ptep = huge_pte_offset(mm, haddr, huge_page_size(h));
|
|
if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) {
|
|
ClearHPageRestoreReserve(new_page);
|
|
|
|
/* Break COW or unshare */
|
|
huge_ptep_clear_flush(vma, haddr, ptep);
|
|
mmu_notifier_invalidate_range(mm, range.start, range.end);
|
|
page_remove_rmap(old_page, vma, true);
|
|
hugepage_add_new_anon_rmap(new_page, vma, haddr);
|
|
set_huge_pte_at(mm, haddr, ptep,
|
|
make_huge_pte(vma, new_page, !unshare));
|
|
SetHPageMigratable(new_page);
|
|
/* Make the old page be freed below */
|
|
new_page = old_page;
|
|
}
|
|
spin_unlock(ptl);
|
|
mmu_notifier_invalidate_range_end(&range);
|
|
out_release_all:
|
|
/*
|
|
* No restore in case of successful pagetable update (Break COW or
|
|
* unshare)
|
|
*/
|
|
if (new_page != old_page)
|
|
restore_reserve_on_error(h, vma, haddr, new_page);
|
|
put_page(new_page);
|
|
out_release_old:
|
|
put_page(old_page);
|
|
|
|
spin_lock(ptl); /* Caller expects lock to be held */
|
|
|
|
delayacct_wpcopy_end();
|
|
return ret;
|
|
}
|
|
|
|
/* Return the pagecache page at a given address within a VMA */
|
|
static struct page *hugetlbfs_pagecache_page(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long address)
|
|
{
|
|
struct address_space *mapping;
|
|
pgoff_t idx;
|
|
|
|
mapping = vma->vm_file->f_mapping;
|
|
idx = vma_hugecache_offset(h, vma, address);
|
|
|
|
return find_lock_page(mapping, idx);
|
|
}
|
|
|
|
/*
|
|
* Return whether there is a pagecache page to back given address within VMA.
|
|
* Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page.
|
|
*/
|
|
static bool hugetlbfs_pagecache_present(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long address)
|
|
{
|
|
struct address_space *mapping;
|
|
pgoff_t idx;
|
|
struct page *page;
|
|
|
|
mapping = vma->vm_file->f_mapping;
|
|
idx = vma_hugecache_offset(h, vma, address);
|
|
|
|
page = find_get_page(mapping, idx);
|
|
if (page)
|
|
put_page(page);
|
|
return page != NULL;
|
|
}
|
|
|
|
int huge_add_to_page_cache(struct page *page, struct address_space *mapping,
|
|
pgoff_t idx)
|
|
{
|
|
struct inode *inode = mapping->host;
|
|
struct hstate *h = hstate_inode(inode);
|
|
int err = add_to_page_cache(page, mapping, idx, GFP_KERNEL);
|
|
|
|
if (err)
|
|
return err;
|
|
ClearHPageRestoreReserve(page);
|
|
|
|
/*
|
|
* set page dirty so that it will not be removed from cache/file
|
|
* by non-hugetlbfs specific code paths.
|
|
*/
|
|
set_page_dirty(page);
|
|
|
|
spin_lock(&inode->i_lock);
|
|
inode->i_blocks += blocks_per_huge_page(h);
|
|
spin_unlock(&inode->i_lock);
|
|
return 0;
|
|
}
|
|
|
|
static inline vm_fault_t hugetlb_handle_userfault(struct vm_area_struct *vma,
|
|
struct address_space *mapping,
|
|
pgoff_t idx,
|
|
unsigned int flags,
|
|
unsigned long haddr,
|
|
unsigned long addr,
|
|
unsigned long reason)
|
|
{
|
|
vm_fault_t ret;
|
|
u32 hash;
|
|
struct vm_fault vmf = {
|
|
.vma = vma,
|
|
.address = haddr,
|
|
.real_address = addr,
|
|
.flags = flags,
|
|
|
|
/*
|
|
* Hard to debug if it ends up being
|
|
* used by a callee that assumes
|
|
* something about the other
|
|
* uninitialized fields... same as in
|
|
* memory.c
|
|
*/
|
|
};
|
|
|
|
/*
|
|
* hugetlb_fault_mutex and i_mmap_rwsem must be
|
|
* dropped before handling userfault. Reacquire
|
|
* after handling fault to make calling code simpler.
|
|
*/
|
|
hash = hugetlb_fault_mutex_hash(mapping, idx);
|
|
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
|
|
i_mmap_unlock_read(mapping);
|
|
ret = handle_userfault(&vmf, reason);
|
|
i_mmap_lock_read(mapping);
|
|
mutex_lock(&hugetlb_fault_mutex_table[hash]);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
|
|
struct vm_area_struct *vma,
|
|
struct address_space *mapping, pgoff_t idx,
|
|
unsigned long address, pte_t *ptep,
|
|
pte_t old_pte, unsigned int flags)
|
|
{
|
|
struct hstate *h = hstate_vma(vma);
|
|
vm_fault_t ret = VM_FAULT_SIGBUS;
|
|
int anon_rmap = 0;
|
|
unsigned long size;
|
|
struct page *page;
|
|
pte_t new_pte;
|
|
spinlock_t *ptl;
|
|
unsigned long haddr = address & huge_page_mask(h);
|
|
bool new_page, new_pagecache_page = false;
|
|
|
|
/*
|
|
* Currently, we are forced to kill the process in the event the
|
|
* original mapper has unmapped pages from the child due to a failed
|
|
* COW/unsharing. Warn that such a situation has occurred as it may not
|
|
* be obvious.
|
|
*/
|
|
if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) {
|
|
pr_warn_ratelimited("PID %d killed due to inadequate hugepage pool\n",
|
|
current->pid);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* We can not race with truncation due to holding i_mmap_rwsem.
|
|
* i_size is modified when holding i_mmap_rwsem, so check here
|
|
* once for faults beyond end of file.
|
|
*/
|
|
size = i_size_read(mapping->host) >> huge_page_shift(h);
|
|
if (idx >= size)
|
|
goto out;
|
|
|
|
retry:
|
|
new_page = false;
|
|
page = find_lock_page(mapping, idx);
|
|
if (!page) {
|
|
/* Check for page in userfault range */
|
|
if (userfaultfd_missing(vma)) {
|
|
ret = hugetlb_handle_userfault(vma, mapping, idx,
|
|
flags, haddr, address,
|
|
VM_UFFD_MISSING);
|
|
goto out;
|
|
}
|
|
|
|
page = alloc_huge_page(vma, haddr, 0);
|
|
if (IS_ERR(page)) {
|
|
/*
|
|
* Returning error will result in faulting task being
|
|
* sent SIGBUS. The hugetlb fault mutex prevents two
|
|
* tasks from racing to fault in the same page which
|
|
* could result in false unable to allocate errors.
|
|
* Page migration does not take the fault mutex, but
|
|
* does a clear then write of pte's under page table
|
|
* lock. Page fault code could race with migration,
|
|
* notice the clear pte and try to allocate a page
|
|
* here. Before returning error, get ptl and make
|
|
* sure there really is no pte entry.
|
|
*/
|
|
ptl = huge_pte_lock(h, mm, ptep);
|
|
ret = 0;
|
|
if (huge_pte_none(huge_ptep_get(ptep)))
|
|
ret = vmf_error(PTR_ERR(page));
|
|
spin_unlock(ptl);
|
|
goto out;
|
|
}
|
|
clear_huge_page(page, address, pages_per_huge_page(h));
|
|
__SetPageUptodate(page);
|
|
new_page = true;
|
|
|
|
if (vma->vm_flags & VM_MAYSHARE) {
|
|
int err = huge_add_to_page_cache(page, mapping, idx);
|
|
if (err) {
|
|
put_page(page);
|
|
if (err == -EEXIST)
|
|
goto retry;
|
|
goto out;
|
|
}
|
|
new_pagecache_page = true;
|
|
} else {
|
|
lock_page(page);
|
|
if (unlikely(anon_vma_prepare(vma))) {
|
|
ret = VM_FAULT_OOM;
|
|
goto backout_unlocked;
|
|
}
|
|
anon_rmap = 1;
|
|
}
|
|
} else {
|
|
/*
|
|
* If memory error occurs between mmap() and fault, some process
|
|
* don't have hwpoisoned swap entry for errored virtual address.
|
|
* So we need to block hugepage fault by PG_hwpoison bit check.
|
|
*/
|
|
if (unlikely(PageHWPoison(page))) {
|
|
ret = VM_FAULT_HWPOISON_LARGE |
|
|
VM_FAULT_SET_HINDEX(hstate_index(h));
|
|
goto backout_unlocked;
|
|
}
|
|
|
|
/* Check for page in userfault range. */
|
|
if (userfaultfd_minor(vma)) {
|
|
unlock_page(page);
|
|
put_page(page);
|
|
ret = hugetlb_handle_userfault(vma, mapping, idx,
|
|
flags, haddr, address,
|
|
VM_UFFD_MINOR);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we are going to COW a private mapping later, we examine the
|
|
* pending reservations for this page now. This will ensure that
|
|
* any allocations necessary to record that reservation occur outside
|
|
* the spinlock.
|
|
*/
|
|
if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
|
|
if (vma_needs_reservation(h, vma, haddr) < 0) {
|
|
ret = VM_FAULT_OOM;
|
|
goto backout_unlocked;
|
|
}
|
|
/* Just decrements count, does not deallocate */
|
|
vma_end_reservation(h, vma, haddr);
|
|
}
|
|
|
|
ptl = huge_pte_lock(h, mm, ptep);
|
|
ret = 0;
|
|
/* If pte changed from under us, retry */
|
|
if (!pte_same(huge_ptep_get(ptep), old_pte))
|
|
goto backout;
|
|
|
|
if (anon_rmap) {
|
|
ClearHPageRestoreReserve(page);
|
|
hugepage_add_new_anon_rmap(page, vma, haddr);
|
|
} else
|
|
page_dup_file_rmap(page, true);
|
|
new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
|
|
&& (vma->vm_flags & VM_SHARED)));
|
|
/*
|
|
* If this pte was previously wr-protected, keep it wr-protected even
|
|
* if populated.
|
|
*/
|
|
if (unlikely(pte_marker_uffd_wp(old_pte)))
|
|
new_pte = huge_pte_wrprotect(huge_pte_mkuffd_wp(new_pte));
|
|
set_huge_pte_at(mm, haddr, ptep, new_pte);
|
|
|
|
hugetlb_count_add(pages_per_huge_page(h), mm);
|
|
if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
|
|
/* Optimization, do the COW without a second fault */
|
|
ret = hugetlb_wp(mm, vma, address, ptep, flags, page, ptl);
|
|
}
|
|
|
|
spin_unlock(ptl);
|
|
|
|
/*
|
|
* Only set HPageMigratable in newly allocated pages. Existing pages
|
|
* found in the pagecache may not have HPageMigratableset if they have
|
|
* been isolated for migration.
|
|
*/
|
|
if (new_page)
|
|
SetHPageMigratable(page);
|
|
|
|
unlock_page(page);
|
|
out:
|
|
return ret;
|
|
|
|
backout:
|
|
spin_unlock(ptl);
|
|
backout_unlocked:
|
|
unlock_page(page);
|
|
/* restore reserve for newly allocated pages not in page cache */
|
|
if (new_page && !new_pagecache_page)
|
|
restore_reserve_on_error(h, vma, haddr, page);
|
|
put_page(page);
|
|
goto out;
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx)
|
|
{
|
|
unsigned long key[2];
|
|
u32 hash;
|
|
|
|
key[0] = (unsigned long) mapping;
|
|
key[1] = idx;
|
|
|
|
hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0);
|
|
|
|
return hash & (num_fault_mutexes - 1);
|
|
}
|
|
#else
|
|
/*
|
|
* For uniprocessor systems we always use a single mutex, so just
|
|
* return 0 and avoid the hashing overhead.
|
|
*/
|
|
u32 hugetlb_fault_mutex_hash(struct address_space *mapping, pgoff_t idx)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
|
|
unsigned long address, unsigned int flags)
|
|
{
|
|
pte_t *ptep, entry;
|
|
spinlock_t *ptl;
|
|
vm_fault_t ret;
|
|
u32 hash;
|
|
pgoff_t idx;
|
|
struct page *page = NULL;
|
|
struct page *pagecache_page = NULL;
|
|
struct hstate *h = hstate_vma(vma);
|
|
struct address_space *mapping;
|
|
int need_wait_lock = 0;
|
|
unsigned long haddr = address & huge_page_mask(h);
|
|
|
|
ptep = huge_pte_offset(mm, haddr, huge_page_size(h));
|
|
if (ptep) {
|
|
/*
|
|
* Since we hold no locks, ptep could be stale. That is
|
|
* OK as we are only making decisions based on content and
|
|
* not actually modifying content here.
|
|
*/
|
|
entry = huge_ptep_get(ptep);
|
|
if (unlikely(is_hugetlb_entry_migration(entry))) {
|
|
migration_entry_wait_huge(vma, mm, ptep);
|
|
return 0;
|
|
} else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
|
|
return VM_FAULT_HWPOISON_LARGE |
|
|
VM_FAULT_SET_HINDEX(hstate_index(h));
|
|
}
|
|
|
|
/*
|
|
* Acquire i_mmap_rwsem before calling huge_pte_alloc and hold
|
|
* until finished with ptep. This serves two purposes:
|
|
* 1) It prevents huge_pmd_unshare from being called elsewhere
|
|
* and making the ptep no longer valid.
|
|
* 2) It synchronizes us with i_size modifications during truncation.
|
|
*
|
|
* ptep could have already be assigned via huge_pte_offset. That
|
|
* is OK, as huge_pte_alloc will return the same value unless
|
|
* something has changed.
|
|
*/
|
|
mapping = vma->vm_file->f_mapping;
|
|
i_mmap_lock_read(mapping);
|
|
ptep = huge_pte_alloc(mm, vma, haddr, huge_page_size(h));
|
|
if (!ptep) {
|
|
i_mmap_unlock_read(mapping);
|
|
return VM_FAULT_OOM;
|
|
}
|
|
|
|
/*
|
|
* Serialize hugepage allocation and instantiation, so that we don't
|
|
* get spurious allocation failures if two CPUs race to instantiate
|
|
* the same page in the page cache.
|
|
*/
|
|
idx = vma_hugecache_offset(h, vma, haddr);
|
|
hash = hugetlb_fault_mutex_hash(mapping, idx);
|
|
mutex_lock(&hugetlb_fault_mutex_table[hash]);
|
|
|
|
entry = huge_ptep_get(ptep);
|
|
/* PTE markers should be handled the same way as none pte */
|
|
if (huge_pte_none_mostly(entry)) {
|
|
ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep,
|
|
entry, flags);
|
|
goto out_mutex;
|
|
}
|
|
|
|
ret = 0;
|
|
|
|
/*
|
|
* entry could be a migration/hwpoison entry at this point, so this
|
|
* check prevents the kernel from going below assuming that we have
|
|
* an active hugepage in pagecache. This goto expects the 2nd page
|
|
* fault, and is_hugetlb_entry_(migration|hwpoisoned) check will
|
|
* properly handle it.
|
|
*/
|
|
if (!pte_present(entry))
|
|
goto out_mutex;
|
|
|
|
/*
|
|
* If we are going to COW/unshare the mapping later, we examine the
|
|
* pending reservations for this page now. This will ensure that any
|
|
* allocations necessary to record that reservation occur outside the
|
|
* spinlock. For private mappings, we also lookup the pagecache
|
|
* page now as it is used to determine if a reservation has been
|
|
* consumed.
|
|
*/
|
|
if ((flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) &&
|
|
!huge_pte_write(entry)) {
|
|
if (vma_needs_reservation(h, vma, haddr) < 0) {
|
|
ret = VM_FAULT_OOM;
|
|
goto out_mutex;
|
|
}
|
|
/* Just decrements count, does not deallocate */
|
|
vma_end_reservation(h, vma, haddr);
|
|
|
|
if (!(vma->vm_flags & VM_MAYSHARE))
|
|
pagecache_page = hugetlbfs_pagecache_page(h,
|
|
vma, haddr);
|
|
}
|
|
|
|
ptl = huge_pte_lock(h, mm, ptep);
|
|
|
|
/* Check for a racing update before calling hugetlb_wp() */
|
|
if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
|
|
goto out_ptl;
|
|
|
|
/* Handle userfault-wp first, before trying to lock more pages */
|
|
if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(ptep)) &&
|
|
(flags & FAULT_FLAG_WRITE) && !huge_pte_write(entry)) {
|
|
struct vm_fault vmf = {
|
|
.vma = vma,
|
|
.address = haddr,
|
|
.real_address = address,
|
|
.flags = flags,
|
|
};
|
|
|
|
spin_unlock(ptl);
|
|
if (pagecache_page) {
|
|
unlock_page(pagecache_page);
|
|
put_page(pagecache_page);
|
|
}
|
|
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
|
|
i_mmap_unlock_read(mapping);
|
|
return handle_userfault(&vmf, VM_UFFD_WP);
|
|
}
|
|
|
|
/*
|
|
* hugetlb_wp() requires page locks of pte_page(entry) and
|
|
* pagecache_page, so here we need take the former one
|
|
* when page != pagecache_page or !pagecache_page.
|
|
*/
|
|
page = pte_page(entry);
|
|
if (page != pagecache_page)
|
|
if (!trylock_page(page)) {
|
|
need_wait_lock = 1;
|
|
goto out_ptl;
|
|
}
|
|
|
|
get_page(page);
|
|
|
|
if (flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) {
|
|
if (!huge_pte_write(entry)) {
|
|
ret = hugetlb_wp(mm, vma, address, ptep, flags,
|
|
pagecache_page, ptl);
|
|
goto out_put_page;
|
|
} else if (likely(flags & FAULT_FLAG_WRITE)) {
|
|
entry = huge_pte_mkdirty(entry);
|
|
}
|
|
}
|
|
entry = pte_mkyoung(entry);
|
|
if (huge_ptep_set_access_flags(vma, haddr, ptep, entry,
|
|
flags & FAULT_FLAG_WRITE))
|
|
update_mmu_cache(vma, haddr, ptep);
|
|
out_put_page:
|
|
if (page != pagecache_page)
|
|
unlock_page(page);
|
|
put_page(page);
|
|
out_ptl:
|
|
spin_unlock(ptl);
|
|
|
|
if (pagecache_page) {
|
|
unlock_page(pagecache_page);
|
|
put_page(pagecache_page);
|
|
}
|
|
out_mutex:
|
|
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
|
|
i_mmap_unlock_read(mapping);
|
|
/*
|
|
* Generally it's safe to hold refcount during waiting page lock. But
|
|
* here we just wait to defer the next page fault to avoid busy loop and
|
|
* the page is not used after unlocked before returning from the current
|
|
* page fault. So we are safe from accessing freed page, even if we wait
|
|
* here without taking refcount.
|
|
*/
|
|
if (need_wait_lock)
|
|
wait_on_page_locked(page);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_USERFAULTFD
|
|
/*
|
|
* Used by userfaultfd UFFDIO_COPY. Based on mcopy_atomic_pte with
|
|
* modifications for huge pages.
|
|
*/
|
|
int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
|
|
pte_t *dst_pte,
|
|
struct vm_area_struct *dst_vma,
|
|
unsigned long dst_addr,
|
|
unsigned long src_addr,
|
|
enum mcopy_atomic_mode mode,
|
|
struct page **pagep,
|
|
bool wp_copy)
|
|
{
|
|
bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE);
|
|
struct hstate *h = hstate_vma(dst_vma);
|
|
struct address_space *mapping = dst_vma->vm_file->f_mapping;
|
|
pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr);
|
|
unsigned long size;
|
|
int vm_shared = dst_vma->vm_flags & VM_SHARED;
|
|
pte_t _dst_pte;
|
|
spinlock_t *ptl;
|
|
int ret = -ENOMEM;
|
|
struct page *page;
|
|
int writable;
|
|
bool page_in_pagecache = false;
|
|
|
|
if (is_continue) {
|
|
ret = -EFAULT;
|
|
page = find_lock_page(mapping, idx);
|
|
if (!page)
|
|
goto out;
|
|
page_in_pagecache = true;
|
|
} else if (!*pagep) {
|
|
/* If a page already exists, then it's UFFDIO_COPY for
|
|
* a non-missing case. Return -EEXIST.
|
|
*/
|
|
if (vm_shared &&
|
|
hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) {
|
|
ret = -EEXIST;
|
|
goto out;
|
|
}
|
|
|
|
page = alloc_huge_page(dst_vma, dst_addr, 0);
|
|
if (IS_ERR(page)) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
ret = copy_huge_page_from_user(page,
|
|
(const void __user *) src_addr,
|
|
pages_per_huge_page(h), false);
|
|
|
|
/* fallback to copy_from_user outside mmap_lock */
|
|
if (unlikely(ret)) {
|
|
ret = -ENOENT;
|
|
/* Free the allocated page which may have
|
|
* consumed a reservation.
|
|
*/
|
|
restore_reserve_on_error(h, dst_vma, dst_addr, page);
|
|
put_page(page);
|
|
|
|
/* Allocate a temporary page to hold the copied
|
|
* contents.
|
|
*/
|
|
page = alloc_huge_page_vma(h, dst_vma, dst_addr);
|
|
if (!page) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
*pagep = page;
|
|
/* Set the outparam pagep and return to the caller to
|
|
* copy the contents outside the lock. Don't free the
|
|
* page.
|
|
*/
|
|
goto out;
|
|
}
|
|
} else {
|
|
if (vm_shared &&
|
|
hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) {
|
|
put_page(*pagep);
|
|
ret = -EEXIST;
|
|
*pagep = NULL;
|
|
goto out;
|
|
}
|
|
|
|
page = alloc_huge_page(dst_vma, dst_addr, 0);
|
|
if (IS_ERR(page)) {
|
|
ret = -ENOMEM;
|
|
*pagep = NULL;
|
|
goto out;
|
|
}
|
|
copy_user_huge_page(page, *pagep, dst_addr, dst_vma,
|
|
pages_per_huge_page(h));
|
|
put_page(*pagep);
|
|
*pagep = NULL;
|
|
}
|
|
|
|
/*
|
|
* The memory barrier inside __SetPageUptodate makes sure that
|
|
* preceding stores to the page contents become visible before
|
|
* the set_pte_at() write.
|
|
*/
|
|
__SetPageUptodate(page);
|
|
|
|
/* Add shared, newly allocated pages to the page cache. */
|
|
if (vm_shared && !is_continue) {
|
|
size = i_size_read(mapping->host) >> huge_page_shift(h);
|
|
ret = -EFAULT;
|
|
if (idx >= size)
|
|
goto out_release_nounlock;
|
|
|
|
/*
|
|
* Serialization between remove_inode_hugepages() and
|
|
* huge_add_to_page_cache() below happens through the
|
|
* hugetlb_fault_mutex_table that here must be hold by
|
|
* the caller.
|
|
*/
|
|
ret = huge_add_to_page_cache(page, mapping, idx);
|
|
if (ret)
|
|
goto out_release_nounlock;
|
|
page_in_pagecache = true;
|
|
}
|
|
|
|
ptl = huge_pte_lockptr(h, dst_mm, dst_pte);
|
|
spin_lock(ptl);
|
|
|
|
/*
|
|
* Recheck the i_size after holding PT lock to make sure not
|
|
* to leave any page mapped (as page_mapped()) beyond the end
|
|
* of the i_size (remove_inode_hugepages() is strict about
|
|
* enforcing that). If we bail out here, we'll also leave a
|
|
* page in the radix tree in the vm_shared case beyond the end
|
|
* of the i_size, but remove_inode_hugepages() will take care
|
|
* of it as soon as we drop the hugetlb_fault_mutex_table.
|
|
*/
|
|
size = i_size_read(mapping->host) >> huge_page_shift(h);
|
|
ret = -EFAULT;
|
|
if (idx >= size)
|
|
goto out_release_unlock;
|
|
|
|
ret = -EEXIST;
|
|
/*
|
|
* We allow to overwrite a pte marker: consider when both MISSING|WP
|
|
* registered, we firstly wr-protect a none pte which has no page cache
|
|
* page backing it, then access the page.
|
|
*/
|
|
if (!huge_pte_none_mostly(huge_ptep_get(dst_pte)))
|
|
goto out_release_unlock;
|
|
|
|
if (vm_shared) {
|
|
page_dup_file_rmap(page, true);
|
|
} else {
|
|
ClearHPageRestoreReserve(page);
|
|
hugepage_add_new_anon_rmap(page, dst_vma, dst_addr);
|
|
}
|
|
|
|
/*
|
|
* For either: (1) CONTINUE on a non-shared VMA, or (2) UFFDIO_COPY
|
|
* with wp flag set, don't set pte write bit.
|
|
*/
|
|
if (wp_copy || (is_continue && !vm_shared))
|
|
writable = 0;
|
|
else
|
|
writable = dst_vma->vm_flags & VM_WRITE;
|
|
|
|
_dst_pte = make_huge_pte(dst_vma, page, writable);
|
|
/*
|
|
* Always mark UFFDIO_COPY page dirty; note that this may not be
|
|
* extremely important for hugetlbfs for now since swapping is not
|
|
* supported, but we should still be clear in that this page cannot be
|
|
* thrown away at will, even if write bit not set.
|
|
*/
|
|
_dst_pte = huge_pte_mkdirty(_dst_pte);
|
|
_dst_pte = pte_mkyoung(_dst_pte);
|
|
|
|
if (wp_copy)
|
|
_dst_pte = huge_pte_mkuffd_wp(_dst_pte);
|
|
|
|
set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
|
|
|
|
(void)huge_ptep_set_access_flags(dst_vma, dst_addr, dst_pte, _dst_pte,
|
|
dst_vma->vm_flags & VM_WRITE);
|
|
hugetlb_count_add(pages_per_huge_page(h), dst_mm);
|
|
|
|
/* No need to invalidate - it was non-present before */
|
|
update_mmu_cache(dst_vma, dst_addr, dst_pte);
|
|
|
|
spin_unlock(ptl);
|
|
if (!is_continue)
|
|
SetHPageMigratable(page);
|
|
if (vm_shared || is_continue)
|
|
unlock_page(page);
|
|
ret = 0;
|
|
out:
|
|
return ret;
|
|
out_release_unlock:
|
|
spin_unlock(ptl);
|
|
if (vm_shared || is_continue)
|
|
unlock_page(page);
|
|
out_release_nounlock:
|
|
if (!page_in_pagecache)
|
|
restore_reserve_on_error(h, dst_vma, dst_addr, page);
|
|
put_page(page);
|
|
goto out;
|
|
}
|
|
#endif /* CONFIG_USERFAULTFD */
|
|
|
|
static void record_subpages_vmas(struct page *page, struct vm_area_struct *vma,
|
|
int refs, struct page **pages,
|
|
struct vm_area_struct **vmas)
|
|
{
|
|
int nr;
|
|
|
|
for (nr = 0; nr < refs; nr++) {
|
|
if (likely(pages))
|
|
pages[nr] = mem_map_offset(page, nr);
|
|
if (vmas)
|
|
vmas[nr] = vma;
|
|
}
|
|
}
|
|
|
|
static inline bool __follow_hugetlb_must_fault(unsigned int flags, pte_t *pte,
|
|
bool *unshare)
|
|
{
|
|
pte_t pteval = huge_ptep_get(pte);
|
|
|
|
*unshare = false;
|
|
if (is_swap_pte(pteval))
|
|
return true;
|
|
if (huge_pte_write(pteval))
|
|
return false;
|
|
if (flags & FOLL_WRITE)
|
|
return true;
|
|
if (gup_must_unshare(flags, pte_page(pteval))) {
|
|
*unshare = true;
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
long follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
|
|
struct page **pages, struct vm_area_struct **vmas,
|
|
unsigned long *position, unsigned long *nr_pages,
|
|
long i, unsigned int flags, int *locked)
|
|
{
|
|
unsigned long pfn_offset;
|
|
unsigned long vaddr = *position;
|
|
unsigned long remainder = *nr_pages;
|
|
struct hstate *h = hstate_vma(vma);
|
|
int err = -EFAULT, refs;
|
|
|
|
while (vaddr < vma->vm_end && remainder) {
|
|
pte_t *pte;
|
|
spinlock_t *ptl = NULL;
|
|
bool unshare = false;
|
|
int absent;
|
|
struct page *page;
|
|
|
|
/*
|
|
* If we have a pending SIGKILL, don't keep faulting pages and
|
|
* potentially allocating memory.
|
|
*/
|
|
if (fatal_signal_pending(current)) {
|
|
remainder = 0;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Some archs (sparc64, sh*) have multiple pte_ts to
|
|
* each hugepage. We have to make sure we get the
|
|
* first, for the page indexing below to work.
|
|
*
|
|
* Note that page table lock is not held when pte is null.
|
|
*/
|
|
pte = huge_pte_offset(mm, vaddr & huge_page_mask(h),
|
|
huge_page_size(h));
|
|
if (pte)
|
|
ptl = huge_pte_lock(h, mm, pte);
|
|
absent = !pte || huge_pte_none(huge_ptep_get(pte));
|
|
|
|
/*
|
|
* When coredumping, it suits get_dump_page if we just return
|
|
* an error where there's an empty slot with no huge pagecache
|
|
* to back it. This way, we avoid allocating a hugepage, and
|
|
* the sparse dumpfile avoids allocating disk blocks, but its
|
|
* huge holes still show up with zeroes where they need to be.
|
|
*/
|
|
if (absent && (flags & FOLL_DUMP) &&
|
|
!hugetlbfs_pagecache_present(h, vma, vaddr)) {
|
|
if (pte)
|
|
spin_unlock(ptl);
|
|
remainder = 0;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* We need call hugetlb_fault for both hugepages under migration
|
|
* (in which case hugetlb_fault waits for the migration,) and
|
|
* hwpoisoned hugepages (in which case we need to prevent the
|
|
* caller from accessing to them.) In order to do this, we use
|
|
* here is_swap_pte instead of is_hugetlb_entry_migration and
|
|
* is_hugetlb_entry_hwpoisoned. This is because it simply covers
|
|
* both cases, and because we can't follow correct pages
|
|
* directly from any kind of swap entries.
|
|
*/
|
|
if (absent ||
|
|
__follow_hugetlb_must_fault(flags, pte, &unshare)) {
|
|
vm_fault_t ret;
|
|
unsigned int fault_flags = 0;
|
|
|
|
if (pte)
|
|
spin_unlock(ptl);
|
|
if (flags & FOLL_WRITE)
|
|
fault_flags |= FAULT_FLAG_WRITE;
|
|
else if (unshare)
|
|
fault_flags |= FAULT_FLAG_UNSHARE;
|
|
if (locked)
|
|
fault_flags |= FAULT_FLAG_ALLOW_RETRY |
|
|
FAULT_FLAG_KILLABLE;
|
|
if (flags & FOLL_NOWAIT)
|
|
fault_flags |= FAULT_FLAG_ALLOW_RETRY |
|
|
FAULT_FLAG_RETRY_NOWAIT;
|
|
if (flags & FOLL_TRIED) {
|
|
/*
|
|
* Note: FAULT_FLAG_ALLOW_RETRY and
|
|
* FAULT_FLAG_TRIED can co-exist
|
|
*/
|
|
fault_flags |= FAULT_FLAG_TRIED;
|
|
}
|
|
ret = hugetlb_fault(mm, vma, vaddr, fault_flags);
|
|
if (ret & VM_FAULT_ERROR) {
|
|
err = vm_fault_to_errno(ret, flags);
|
|
remainder = 0;
|
|
break;
|
|
}
|
|
if (ret & VM_FAULT_RETRY) {
|
|
if (locked &&
|
|
!(fault_flags & FAULT_FLAG_RETRY_NOWAIT))
|
|
*locked = 0;
|
|
*nr_pages = 0;
|
|
/*
|
|
* VM_FAULT_RETRY must not return an
|
|
* error, it will return zero
|
|
* instead.
|
|
*
|
|
* No need to update "position" as the
|
|
* caller will not check it after
|
|
* *nr_pages is set to 0.
|
|
*/
|
|
return i;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
|
|
page = pte_page(huge_ptep_get(pte));
|
|
|
|
VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) &&
|
|
!PageAnonExclusive(page), page);
|
|
|
|
/*
|
|
* If subpage information not requested, update counters
|
|
* and skip the same_page loop below.
|
|
*/
|
|
if (!pages && !vmas && !pfn_offset &&
|
|
(vaddr + huge_page_size(h) < vma->vm_end) &&
|
|
(remainder >= pages_per_huge_page(h))) {
|
|
vaddr += huge_page_size(h);
|
|
remainder -= pages_per_huge_page(h);
|
|
i += pages_per_huge_page(h);
|
|
spin_unlock(ptl);
|
|
continue;
|
|
}
|
|
|
|
/* vaddr may not be aligned to PAGE_SIZE */
|
|
refs = min3(pages_per_huge_page(h) - pfn_offset, remainder,
|
|
(vma->vm_end - ALIGN_DOWN(vaddr, PAGE_SIZE)) >> PAGE_SHIFT);
|
|
|
|
if (pages || vmas)
|
|
record_subpages_vmas(mem_map_offset(page, pfn_offset),
|
|
vma, refs,
|
|
likely(pages) ? pages + i : NULL,
|
|
vmas ? vmas + i : NULL);
|
|
|
|
if (pages) {
|
|
/*
|
|
* try_grab_folio() should always succeed here,
|
|
* because: a) we hold the ptl lock, and b) we've just
|
|
* checked that the huge page is present in the page
|
|
* tables. If the huge page is present, then the tail
|
|
* pages must also be present. The ptl prevents the
|
|
* head page and tail pages from being rearranged in
|
|
* any way. So this page must be available at this
|
|
* point, unless the page refcount overflowed:
|
|
*/
|
|
if (WARN_ON_ONCE(!try_grab_folio(pages[i], refs,
|
|
flags))) {
|
|
spin_unlock(ptl);
|
|
remainder = 0;
|
|
err = -ENOMEM;
|
|
break;
|
|
}
|
|
}
|
|
|
|
vaddr += (refs << PAGE_SHIFT);
|
|
remainder -= refs;
|
|
i += refs;
|
|
|
|
spin_unlock(ptl);
|
|
}
|
|
*nr_pages = remainder;
|
|
/*
|
|
* setting position is actually required only if remainder is
|
|
* not zero but it's faster not to add a "if (remainder)"
|
|
* branch.
|
|
*/
|
|
*position = vaddr;
|
|
|
|
return i ? i : err;
|
|
}
|
|
|
|
unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
|
|
unsigned long address, unsigned long end,
|
|
pgprot_t newprot, unsigned long cp_flags)
|
|
{
|
|
struct mm_struct *mm = vma->vm_mm;
|
|
unsigned long start = address;
|
|
pte_t *ptep;
|
|
pte_t pte;
|
|
struct hstate *h = hstate_vma(vma);
|
|
unsigned long pages = 0, psize = huge_page_size(h);
|
|
bool shared_pmd = false;
|
|
struct mmu_notifier_range range;
|
|
bool uffd_wp = cp_flags & MM_CP_UFFD_WP;
|
|
bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE;
|
|
|
|
/*
|
|
* In the case of shared PMDs, the area to flush could be beyond
|
|
* start/end. Set range.start/range.end to cover the maximum possible
|
|
* range if PMD sharing is possible.
|
|
*/
|
|
mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_VMA,
|
|
0, vma, mm, start, end);
|
|
adjust_range_if_pmd_sharing_possible(vma, &range.start, &range.end);
|
|
|
|
BUG_ON(address >= end);
|
|
flush_cache_range(vma, range.start, range.end);
|
|
|
|
mmu_notifier_invalidate_range_start(&range);
|
|
i_mmap_lock_write(vma->vm_file->f_mapping);
|
|
for (; address < end; address += psize) {
|
|
spinlock_t *ptl;
|
|
ptep = huge_pte_offset(mm, address, psize);
|
|
if (!ptep)
|
|
continue;
|
|
ptl = huge_pte_lock(h, mm, ptep);
|
|
if (huge_pmd_unshare(mm, vma, &address, ptep)) {
|
|
/*
|
|
* When uffd-wp is enabled on the vma, unshare
|
|
* shouldn't happen at all. Warn about it if it
|
|
* happened due to some reason.
|
|
*/
|
|
WARN_ON_ONCE(uffd_wp || uffd_wp_resolve);
|
|
pages++;
|
|
spin_unlock(ptl);
|
|
shared_pmd = true;
|
|
continue;
|
|
}
|
|
pte = huge_ptep_get(ptep);
|
|
if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) {
|
|
spin_unlock(ptl);
|
|
continue;
|
|
}
|
|
if (unlikely(is_hugetlb_entry_migration(pte))) {
|
|
swp_entry_t entry = pte_to_swp_entry(pte);
|
|
struct page *page = pfn_swap_entry_to_page(entry);
|
|
|
|
if (!is_readable_migration_entry(entry)) {
|
|
pte_t newpte;
|
|
|
|
if (PageAnon(page))
|
|
entry = make_readable_exclusive_migration_entry(
|
|
swp_offset(entry));
|
|
else
|
|
entry = make_readable_migration_entry(
|
|
swp_offset(entry));
|
|
newpte = swp_entry_to_pte(entry);
|
|
if (uffd_wp)
|
|
newpte = pte_swp_mkuffd_wp(newpte);
|
|
else if (uffd_wp_resolve)
|
|
newpte = pte_swp_clear_uffd_wp(newpte);
|
|
set_huge_swap_pte_at(mm, address, ptep,
|
|
newpte, psize);
|
|
pages++;
|
|
}
|
|
spin_unlock(ptl);
|
|
continue;
|
|
}
|
|
if (unlikely(pte_marker_uffd_wp(pte))) {
|
|
/*
|
|
* This is changing a non-present pte into a none pte,
|
|
* no need for huge_ptep_modify_prot_start/commit().
|
|
*/
|
|
if (uffd_wp_resolve)
|
|
huge_pte_clear(mm, address, ptep, psize);
|
|
}
|
|
if (!huge_pte_none(pte)) {
|
|
pte_t old_pte;
|
|
unsigned int shift = huge_page_shift(hstate_vma(vma));
|
|
|
|
old_pte = huge_ptep_modify_prot_start(vma, address, ptep);
|
|
pte = huge_pte_modify(old_pte, newprot);
|
|
pte = arch_make_huge_pte(pte, shift, vma->vm_flags);
|
|
if (uffd_wp)
|
|
pte = huge_pte_mkuffd_wp(huge_pte_wrprotect(pte));
|
|
else if (uffd_wp_resolve)
|
|
pte = huge_pte_clear_uffd_wp(pte);
|
|
huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte);
|
|
pages++;
|
|
} else {
|
|
/* None pte */
|
|
if (unlikely(uffd_wp))
|
|
/* Safe to modify directly (none->non-present). */
|
|
set_huge_pte_at(mm, address, ptep,
|
|
make_pte_marker(PTE_MARKER_UFFD_WP));
|
|
}
|
|
spin_unlock(ptl);
|
|
}
|
|
/*
|
|
* Must flush TLB before releasing i_mmap_rwsem: x86's huge_pmd_unshare
|
|
* may have cleared our pud entry and done put_page on the page table:
|
|
* once we release i_mmap_rwsem, another task can do the final put_page
|
|
* and that page table be reused and filled with junk. If we actually
|
|
* did unshare a page of pmds, flush the range corresponding to the pud.
|
|
*/
|
|
if (shared_pmd)
|
|
flush_hugetlb_tlb_range(vma, range.start, range.end);
|
|
else
|
|
flush_hugetlb_tlb_range(vma, start, end);
|
|
/*
|
|
* No need to call mmu_notifier_invalidate_range() we are downgrading
|
|
* page table protection not changing it to point to a new page.
|
|
*
|
|
* See Documentation/vm/mmu_notifier.rst
|
|
*/
|
|
i_mmap_unlock_write(vma->vm_file->f_mapping);
|
|
mmu_notifier_invalidate_range_end(&range);
|
|
|
|
return pages << h->order;
|
|
}
|
|
|
|
/* Return true if reservation was successful, false otherwise. */
|
|
bool hugetlb_reserve_pages(struct inode *inode,
|
|
long from, long to,
|
|
struct vm_area_struct *vma,
|
|
vm_flags_t vm_flags)
|
|
{
|
|
long chg, add = -1;
|
|
struct hstate *h = hstate_inode(inode);
|
|
struct hugepage_subpool *spool = subpool_inode(inode);
|
|
struct resv_map *resv_map;
|
|
struct hugetlb_cgroup *h_cg = NULL;
|
|
long gbl_reserve, regions_needed = 0;
|
|
|
|
/* This should never happen */
|
|
if (from > to) {
|
|
VM_WARN(1, "%s called with a negative range\n", __func__);
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Only apply hugepage reservation if asked. At fault time, an
|
|
* attempt will be made for VM_NORESERVE to allocate a page
|
|
* without using reserves
|
|
*/
|
|
if (vm_flags & VM_NORESERVE)
|
|
return true;
|
|
|
|
/*
|
|
* Shared mappings base their reservation on the number of pages that
|
|
* are already allocated on behalf of the file. Private mappings need
|
|
* to reserve the full area even if read-only as mprotect() may be
|
|
* called to make the mapping read-write. Assume !vma is a shm mapping
|
|
*/
|
|
if (!vma || vma->vm_flags & VM_MAYSHARE) {
|
|
/*
|
|
* resv_map can not be NULL as hugetlb_reserve_pages is only
|
|
* called for inodes for which resv_maps were created (see
|
|
* hugetlbfs_get_inode).
|
|
*/
|
|
resv_map = inode_resv_map(inode);
|
|
|
|
chg = region_chg(resv_map, from, to, ®ions_needed);
|
|
|
|
} else {
|
|
/* Private mapping. */
|
|
resv_map = resv_map_alloc();
|
|
if (!resv_map)
|
|
return false;
|
|
|
|
chg = to - from;
|
|
|
|
set_vma_resv_map(vma, resv_map);
|
|
set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
|
|
}
|
|
|
|
if (chg < 0)
|
|
goto out_err;
|
|
|
|
if (hugetlb_cgroup_charge_cgroup_rsvd(hstate_index(h),
|
|
chg * pages_per_huge_page(h), &h_cg) < 0)
|
|
goto out_err;
|
|
|
|
if (vma && !(vma->vm_flags & VM_MAYSHARE) && h_cg) {
|
|
/* For private mappings, the hugetlb_cgroup uncharge info hangs
|
|
* of the resv_map.
|
|
*/
|
|
resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, h_cg, h);
|
|
}
|
|
|
|
/*
|
|
* There must be enough pages in the subpool for the mapping. If
|
|
* the subpool has a minimum size, there may be some global
|
|
* reservations already in place (gbl_reserve).
|
|
*/
|
|
gbl_reserve = hugepage_subpool_get_pages(spool, chg);
|
|
if (gbl_reserve < 0)
|
|
goto out_uncharge_cgroup;
|
|
|
|
/*
|
|
* Check enough hugepages are available for the reservation.
|
|
* Hand the pages back to the subpool if there are not
|
|
*/
|
|
if (hugetlb_acct_memory(h, gbl_reserve) < 0)
|
|
goto out_put_pages;
|
|
|
|
/*
|
|
* Account for the reservations made. Shared mappings record regions
|
|
* that have reservations as they are shared by multiple VMAs.
|
|
* When the last VMA disappears, the region map says how much
|
|
* the reservation was and the page cache tells how much of
|
|
* the reservation was consumed. Private mappings are per-VMA and
|
|
* only the consumed reservations are tracked. When the VMA
|
|
* disappears, the original reservation is the VMA size and the
|
|
* consumed reservations are stored in the map. Hence, nothing
|
|
* else has to be done for private mappings here
|
|
*/
|
|
if (!vma || vma->vm_flags & VM_MAYSHARE) {
|
|
add = region_add(resv_map, from, to, regions_needed, h, h_cg);
|
|
|
|
if (unlikely(add < 0)) {
|
|
hugetlb_acct_memory(h, -gbl_reserve);
|
|
goto out_put_pages;
|
|
} else if (unlikely(chg > add)) {
|
|
/*
|
|
* pages in this range were added to the reserve
|
|
* map between region_chg and region_add. This
|
|
* indicates a race with alloc_huge_page. Adjust
|
|
* the subpool and reserve counts modified above
|
|
* based on the difference.
|
|
*/
|
|
long rsv_adjust;
|
|
|
|
/*
|
|
* hugetlb_cgroup_uncharge_cgroup_rsvd() will put the
|
|
* reference to h_cg->css. See comment below for detail.
|
|
*/
|
|
hugetlb_cgroup_uncharge_cgroup_rsvd(
|
|
hstate_index(h),
|
|
(chg - add) * pages_per_huge_page(h), h_cg);
|
|
|
|
rsv_adjust = hugepage_subpool_put_pages(spool,
|
|
chg - add);
|
|
hugetlb_acct_memory(h, -rsv_adjust);
|
|
} else if (h_cg) {
|
|
/*
|
|
* The file_regions will hold their own reference to
|
|
* h_cg->css. So we should release the reference held
|
|
* via hugetlb_cgroup_charge_cgroup_rsvd() when we are
|
|
* done.
|
|
*/
|
|
hugetlb_cgroup_put_rsvd_cgroup(h_cg);
|
|
}
|
|
}
|
|
return true;
|
|
|
|
out_put_pages:
|
|
/* put back original number of pages, chg */
|
|
(void)hugepage_subpool_put_pages(spool, chg);
|
|
out_uncharge_cgroup:
|
|
hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h),
|
|
chg * pages_per_huge_page(h), h_cg);
|
|
out_err:
|
|
if (!vma || vma->vm_flags & VM_MAYSHARE)
|
|
/* Only call region_abort if the region_chg succeeded but the
|
|
* region_add failed or didn't run.
|
|
*/
|
|
if (chg >= 0 && add < 0)
|
|
region_abort(resv_map, from, to, regions_needed);
|
|
if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER))
|
|
kref_put(&resv_map->refs, resv_map_release);
|
|
return false;
|
|
}
|
|
|
|
long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
|
|
long freed)
|
|
{
|
|
struct hstate *h = hstate_inode(inode);
|
|
struct resv_map *resv_map = inode_resv_map(inode);
|
|
long chg = 0;
|
|
struct hugepage_subpool *spool = subpool_inode(inode);
|
|
long gbl_reserve;
|
|
|
|
/*
|
|
* Since this routine can be called in the evict inode path for all
|
|
* hugetlbfs inodes, resv_map could be NULL.
|
|
*/
|
|
if (resv_map) {
|
|
chg = region_del(resv_map, start, end);
|
|
/*
|
|
* region_del() can fail in the rare case where a region
|
|
* must be split and another region descriptor can not be
|
|
* allocated. If end == LONG_MAX, it will not fail.
|
|
*/
|
|
if (chg < 0)
|
|
return chg;
|
|
}
|
|
|
|
spin_lock(&inode->i_lock);
|
|
inode->i_blocks -= (blocks_per_huge_page(h) * freed);
|
|
spin_unlock(&inode->i_lock);
|
|
|
|
/*
|
|
* If the subpool has a minimum size, the number of global
|
|
* reservations to be released may be adjusted.
|
|
*
|
|
* Note that !resv_map implies freed == 0. So (chg - freed)
|
|
* won't go negative.
|
|
*/
|
|
gbl_reserve = hugepage_subpool_put_pages(spool, (chg - freed));
|
|
hugetlb_acct_memory(h, -gbl_reserve);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
|
|
static unsigned long page_table_shareable(struct vm_area_struct *svma,
|
|
struct vm_area_struct *vma,
|
|
unsigned long addr, pgoff_t idx)
|
|
{
|
|
unsigned long saddr = ((idx - svma->vm_pgoff) << PAGE_SHIFT) +
|
|
svma->vm_start;
|
|
unsigned long sbase = saddr & PUD_MASK;
|
|
unsigned long s_end = sbase + PUD_SIZE;
|
|
|
|
/* Allow segments to share if only one is marked locked */
|
|
unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK;
|
|
unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK;
|
|
|
|
/*
|
|
* match the virtual addresses, permission and the alignment of the
|
|
* page table page.
|
|
*/
|
|
if (pmd_index(addr) != pmd_index(saddr) ||
|
|
vm_flags != svm_flags ||
|
|
!range_in_vma(svma, sbase, s_end))
|
|
return 0;
|
|
|
|
return saddr;
|
|
}
|
|
|
|
static bool vma_shareable(struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
unsigned long base = addr & PUD_MASK;
|
|
unsigned long end = base + PUD_SIZE;
|
|
|
|
/*
|
|
* check on proper vm_flags and page table alignment
|
|
*/
|
|
if (vma->vm_flags & VM_MAYSHARE && range_in_vma(vma, base, end))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
#ifdef CONFIG_USERFAULTFD
|
|
if (uffd_disable_huge_pmd_share(vma))
|
|
return false;
|
|
#endif
|
|
return vma_shareable(vma, addr);
|
|
}
|
|
|
|
/*
|
|
* Determine if start,end range within vma could be mapped by shared pmd.
|
|
* If yes, adjust start and end to cover range associated with possible
|
|
* shared pmd mappings.
|
|
*/
|
|
void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma,
|
|
unsigned long *start, unsigned long *end)
|
|
{
|
|
unsigned long v_start = ALIGN(vma->vm_start, PUD_SIZE),
|
|
v_end = ALIGN_DOWN(vma->vm_end, PUD_SIZE);
|
|
|
|
/*
|
|
* vma needs to span at least one aligned PUD size, and the range
|
|
* must be at least partially within in.
|
|
*/
|
|
if (!(vma->vm_flags & VM_MAYSHARE) || !(v_end > v_start) ||
|
|
(*end <= v_start) || (*start >= v_end))
|
|
return;
|
|
|
|
/* Extend the range to be PUD aligned for a worst case scenario */
|
|
if (*start > v_start)
|
|
*start = ALIGN_DOWN(*start, PUD_SIZE);
|
|
|
|
if (*end < v_end)
|
|
*end = ALIGN(*end, PUD_SIZE);
|
|
}
|
|
|
|
/*
|
|
* Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc()
|
|
* and returns the corresponding pte. While this is not necessary for the
|
|
* !shared pmd case because we can allocate the pmd later as well, it makes the
|
|
* code much cleaner.
|
|
*
|
|
* This routine must be called with i_mmap_rwsem held in at least read mode if
|
|
* sharing is possible. For hugetlbfs, this prevents removal of any page
|
|
* table entries associated with the address space. This is important as we
|
|
* are setting up sharing based on existing page table entries (mappings).
|
|
*/
|
|
pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma,
|
|
unsigned long addr, pud_t *pud)
|
|
{
|
|
struct address_space *mapping = vma->vm_file->f_mapping;
|
|
pgoff_t idx = ((addr - vma->vm_start) >> PAGE_SHIFT) +
|
|
vma->vm_pgoff;
|
|
struct vm_area_struct *svma;
|
|
unsigned long saddr;
|
|
pte_t *spte = NULL;
|
|
pte_t *pte;
|
|
spinlock_t *ptl;
|
|
|
|
i_mmap_assert_locked(mapping);
|
|
vma_interval_tree_foreach(svma, &mapping->i_mmap, idx, idx) {
|
|
if (svma == vma)
|
|
continue;
|
|
|
|
saddr = page_table_shareable(svma, vma, addr, idx);
|
|
if (saddr) {
|
|
spte = huge_pte_offset(svma->vm_mm, saddr,
|
|
vma_mmu_pagesize(svma));
|
|
if (spte) {
|
|
get_page(virt_to_page(spte));
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!spte)
|
|
goto out;
|
|
|
|
ptl = huge_pte_lock(hstate_vma(vma), mm, spte);
|
|
if (pud_none(*pud)) {
|
|
pud_populate(mm, pud,
|
|
(pmd_t *)((unsigned long)spte & PAGE_MASK));
|
|
mm_inc_nr_pmds(mm);
|
|
} else {
|
|
put_page(virt_to_page(spte));
|
|
}
|
|
spin_unlock(ptl);
|
|
out:
|
|
pte = (pte_t *)pmd_alloc(mm, pud, addr);
|
|
return pte;
|
|
}
|
|
|
|
/*
|
|
* unmap huge page backed by shared pte.
|
|
*
|
|
* Hugetlb pte page is ref counted at the time of mapping. If pte is shared
|
|
* indicated by page_count > 1, unmap is achieved by clearing pud and
|
|
* decrementing the ref count. If count == 1, the pte page is not shared.
|
|
*
|
|
* Called with page table lock held and i_mmap_rwsem held in write mode.
|
|
*
|
|
* returns: 1 successfully unmapped a shared pte page
|
|
* 0 the underlying pte page is not shared, or it is the last user
|
|
*/
|
|
int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma,
|
|
unsigned long *addr, pte_t *ptep)
|
|
{
|
|
pgd_t *pgd = pgd_offset(mm, *addr);
|
|
p4d_t *p4d = p4d_offset(pgd, *addr);
|
|
pud_t *pud = pud_offset(p4d, *addr);
|
|
|
|
i_mmap_assert_write_locked(vma->vm_file->f_mapping);
|
|
BUG_ON(page_count(virt_to_page(ptep)) == 0);
|
|
if (page_count(virt_to_page(ptep)) == 1)
|
|
return 0;
|
|
|
|
pud_clear(pud);
|
|
put_page(virt_to_page(ptep));
|
|
mm_dec_nr_pmds(mm);
|
|
/*
|
|
* This update of passed address optimizes loops sequentially
|
|
* processing addresses in increments of huge page size (PMD_SIZE
|
|
* in this case). By clearing the pud, a PUD_SIZE area is unmapped.
|
|
* Update address to the 'last page' in the cleared area so that
|
|
* calling loop can move to first page past this area.
|
|
*/
|
|
*addr |= PUD_SIZE - PMD_SIZE;
|
|
return 1;
|
|
}
|
|
|
|
#else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
|
|
pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma,
|
|
unsigned long addr, pud_t *pud)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma,
|
|
unsigned long *addr, pte_t *ptep)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma,
|
|
unsigned long *start, unsigned long *end)
|
|
{
|
|
}
|
|
|
|
bool want_pmd_share(struct vm_area_struct *vma, unsigned long addr)
|
|
{
|
|
return false;
|
|
}
|
|
#endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
|
|
|
|
#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
|
|
pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
|
|
unsigned long addr, unsigned long sz)
|
|
{
|
|
pgd_t *pgd;
|
|
p4d_t *p4d;
|
|
pud_t *pud;
|
|
pte_t *pte = NULL;
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
p4d = p4d_alloc(mm, pgd, addr);
|
|
if (!p4d)
|
|
return NULL;
|
|
pud = pud_alloc(mm, p4d, addr);
|
|
if (pud) {
|
|
if (sz == PUD_SIZE) {
|
|
pte = (pte_t *)pud;
|
|
} else {
|
|
BUG_ON(sz != PMD_SIZE);
|
|
if (want_pmd_share(vma, addr) && pud_none(*pud))
|
|
pte = huge_pmd_share(mm, vma, addr, pud);
|
|
else
|
|
pte = (pte_t *)pmd_alloc(mm, pud, addr);
|
|
}
|
|
}
|
|
BUG_ON(pte && pte_present(*pte) && !pte_huge(*pte));
|
|
|
|
return pte;
|
|
}
|
|
|
|
/*
|
|
* huge_pte_offset() - Walk the page table to resolve the hugepage
|
|
* entry at address @addr
|
|
*
|
|
* Return: Pointer to page table entry (PUD or PMD) for
|
|
* address @addr, or NULL if a !p*d_present() entry is encountered and the
|
|
* size @sz doesn't match the hugepage size at this level of the page
|
|
* table.
|
|
*/
|
|
pte_t *huge_pte_offset(struct mm_struct *mm,
|
|
unsigned long addr, unsigned long sz)
|
|
{
|
|
pgd_t *pgd;
|
|
p4d_t *p4d;
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
if (!pgd_present(*pgd))
|
|
return NULL;
|
|
p4d = p4d_offset(pgd, addr);
|
|
if (!p4d_present(*p4d))
|
|
return NULL;
|
|
|
|
pud = pud_offset(p4d, addr);
|
|
if (sz == PUD_SIZE)
|
|
/* must be pud huge, non-present or none */
|
|
return (pte_t *)pud;
|
|
if (!pud_present(*pud))
|
|
return NULL;
|
|
/* must have a valid entry and size to go further */
|
|
|
|
pmd = pmd_offset(pud, addr);
|
|
/* must be pmd huge, non-present or none */
|
|
return (pte_t *)pmd;
|
|
}
|
|
|
|
#endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
|
|
|
|
/*
|
|
* These functions are overwritable if your architecture needs its own
|
|
* behavior.
|
|
*/
|
|
struct page * __weak
|
|
follow_huge_addr(struct mm_struct *mm, unsigned long address,
|
|
int write)
|
|
{
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
struct page * __weak
|
|
follow_huge_pd(struct vm_area_struct *vma,
|
|
unsigned long address, hugepd_t hpd, int flags, int pdshift)
|
|
{
|
|
WARN(1, "hugepd follow called with no support for hugepage directory format\n");
|
|
return NULL;
|
|
}
|
|
|
|
struct page * __weak
|
|
follow_huge_pmd(struct mm_struct *mm, unsigned long address,
|
|
pmd_t *pmd, int flags)
|
|
{
|
|
struct page *page = NULL;
|
|
spinlock_t *ptl;
|
|
pte_t pte;
|
|
|
|
/*
|
|
* FOLL_PIN is not supported for follow_page(). Ordinary GUP goes via
|
|
* follow_hugetlb_page().
|
|
*/
|
|
if (WARN_ON_ONCE(flags & FOLL_PIN))
|
|
return NULL;
|
|
|
|
retry:
|
|
ptl = pmd_lockptr(mm, pmd);
|
|
spin_lock(ptl);
|
|
/*
|
|
* make sure that the address range covered by this pmd is not
|
|
* unmapped from other threads.
|
|
*/
|
|
if (!pmd_huge(*pmd))
|
|
goto out;
|
|
pte = huge_ptep_get((pte_t *)pmd);
|
|
if (pte_present(pte)) {
|
|
page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT);
|
|
/*
|
|
* try_grab_page() should always succeed here, because: a) we
|
|
* hold the pmd (ptl) lock, and b) we've just checked that the
|
|
* huge pmd (head) page is present in the page tables. The ptl
|
|
* prevents the head page and tail pages from being rearranged
|
|
* in any way. So this page must be available at this point,
|
|
* unless the page refcount overflowed:
|
|
*/
|
|
if (WARN_ON_ONCE(!try_grab_page(page, flags))) {
|
|
page = NULL;
|
|
goto out;
|
|
}
|
|
} else {
|
|
if (is_hugetlb_entry_migration(pte)) {
|
|
spin_unlock(ptl);
|
|
__migration_entry_wait(mm, (pte_t *)pmd, ptl);
|
|
goto retry;
|
|
}
|
|
/*
|
|
* hwpoisoned entry is treated as no_page_table in
|
|
* follow_page_mask().
|
|
*/
|
|
}
|
|
out:
|
|
spin_unlock(ptl);
|
|
return page;
|
|
}
|
|
|
|
struct page * __weak
|
|
follow_huge_pud(struct mm_struct *mm, unsigned long address,
|
|
pud_t *pud, int flags)
|
|
{
|
|
if (flags & (FOLL_GET | FOLL_PIN))
|
|
return NULL;
|
|
|
|
return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
|
|
}
|
|
|
|
struct page * __weak
|
|
follow_huge_pgd(struct mm_struct *mm, unsigned long address, pgd_t *pgd, int flags)
|
|
{
|
|
if (flags & (FOLL_GET | FOLL_PIN))
|
|
return NULL;
|
|
|
|
return pte_page(*(pte_t *)pgd) + ((address & ~PGDIR_MASK) >> PAGE_SHIFT);
|
|
}
|
|
|
|
bool isolate_huge_page(struct page *page, struct list_head *list)
|
|
{
|
|
bool ret = true;
|
|
|
|
spin_lock_irq(&hugetlb_lock);
|
|
if (!PageHeadHuge(page) ||
|
|
!HPageMigratable(page) ||
|
|
!get_page_unless_zero(page)) {
|
|
ret = false;
|
|
goto unlock;
|
|
}
|
|
ClearHPageMigratable(page);
|
|
list_move_tail(&page->lru, list);
|
|
unlock:
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
return ret;
|
|
}
|
|
|
|
int get_hwpoison_huge_page(struct page *page, bool *hugetlb)
|
|
{
|
|
int ret = 0;
|
|
|
|
*hugetlb = false;
|
|
spin_lock_irq(&hugetlb_lock);
|
|
if (PageHeadHuge(page)) {
|
|
*hugetlb = true;
|
|
if (HPageFreed(page))
|
|
ret = 0;
|
|
else if (HPageMigratable(page))
|
|
ret = get_page_unless_zero(page);
|
|
else
|
|
ret = -EBUSY;
|
|
}
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
return ret;
|
|
}
|
|
|
|
int get_huge_page_for_hwpoison(unsigned long pfn, int flags)
|
|
{
|
|
int ret;
|
|
|
|
spin_lock_irq(&hugetlb_lock);
|
|
ret = __get_huge_page_for_hwpoison(pfn, flags);
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
return ret;
|
|
}
|
|
|
|
void putback_active_hugepage(struct page *page)
|
|
{
|
|
spin_lock_irq(&hugetlb_lock);
|
|
SetHPageMigratable(page);
|
|
list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist);
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
put_page(page);
|
|
}
|
|
|
|
void move_hugetlb_state(struct page *oldpage, struct page *newpage, int reason)
|
|
{
|
|
struct hstate *h = page_hstate(oldpage);
|
|
|
|
hugetlb_cgroup_migrate(oldpage, newpage);
|
|
set_page_owner_migrate_reason(newpage, reason);
|
|
|
|
/*
|
|
* transfer temporary state of the new huge page. This is
|
|
* reverse to other transitions because the newpage is going to
|
|
* be final while the old one will be freed so it takes over
|
|
* the temporary status.
|
|
*
|
|
* Also note that we have to transfer the per-node surplus state
|
|
* here as well otherwise the global surplus count will not match
|
|
* the per-node's.
|
|
*/
|
|
if (HPageTemporary(newpage)) {
|
|
int old_nid = page_to_nid(oldpage);
|
|
int new_nid = page_to_nid(newpage);
|
|
|
|
SetHPageTemporary(oldpage);
|
|
ClearHPageTemporary(newpage);
|
|
|
|
/*
|
|
* There is no need to transfer the per-node surplus state
|
|
* when we do not cross the node.
|
|
*/
|
|
if (new_nid == old_nid)
|
|
return;
|
|
spin_lock_irq(&hugetlb_lock);
|
|
if (h->surplus_huge_pages_node[old_nid]) {
|
|
h->surplus_huge_pages_node[old_nid]--;
|
|
h->surplus_huge_pages_node[new_nid]++;
|
|
}
|
|
spin_unlock_irq(&hugetlb_lock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This function will unconditionally remove all the shared pmd pgtable entries
|
|
* within the specific vma for a hugetlbfs memory range.
|
|
*/
|
|
void hugetlb_unshare_all_pmds(struct vm_area_struct *vma)
|
|
{
|
|
struct hstate *h = hstate_vma(vma);
|
|
unsigned long sz = huge_page_size(h);
|
|
struct mm_struct *mm = vma->vm_mm;
|
|
struct mmu_notifier_range range;
|
|
unsigned long address, start, end;
|
|
spinlock_t *ptl;
|
|
pte_t *ptep;
|
|
|
|
if (!(vma->vm_flags & VM_MAYSHARE))
|
|
return;
|
|
|
|
start = ALIGN(vma->vm_start, PUD_SIZE);
|
|
end = ALIGN_DOWN(vma->vm_end, PUD_SIZE);
|
|
|
|
if (start >= end)
|
|
return;
|
|
|
|
flush_cache_range(vma, start, end);
|
|
/*
|
|
* No need to call adjust_range_if_pmd_sharing_possible(), because
|
|
* we have already done the PUD_SIZE alignment.
|
|
*/
|
|
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, mm,
|
|
start, end);
|
|
mmu_notifier_invalidate_range_start(&range);
|
|
i_mmap_lock_write(vma->vm_file->f_mapping);
|
|
for (address = start; address < end; address += PUD_SIZE) {
|
|
unsigned long tmp = address;
|
|
|
|
ptep = huge_pte_offset(mm, address, sz);
|
|
if (!ptep)
|
|
continue;
|
|
ptl = huge_pte_lock(h, mm, ptep);
|
|
/* We don't want 'address' to be changed */
|
|
huge_pmd_unshare(mm, vma, &tmp, ptep);
|
|
spin_unlock(ptl);
|
|
}
|
|
flush_hugetlb_tlb_range(vma, start, end);
|
|
i_mmap_unlock_write(vma->vm_file->f_mapping);
|
|
/*
|
|
* No need to call mmu_notifier_invalidate_range(), see
|
|
* Documentation/vm/mmu_notifier.rst.
|
|
*/
|
|
mmu_notifier_invalidate_range_end(&range);
|
|
}
|
|
|
|
#ifdef CONFIG_CMA
|
|
static bool cma_reserve_called __initdata;
|
|
|
|
static int __init cmdline_parse_hugetlb_cma(char *p)
|
|
{
|
|
int nid, count = 0;
|
|
unsigned long tmp;
|
|
char *s = p;
|
|
|
|
while (*s) {
|
|
if (sscanf(s, "%lu%n", &tmp, &count) != 1)
|
|
break;
|
|
|
|
if (s[count] == ':') {
|
|
if (tmp >= MAX_NUMNODES)
|
|
break;
|
|
nid = array_index_nospec(tmp, MAX_NUMNODES);
|
|
|
|
s += count + 1;
|
|
tmp = memparse(s, &s);
|
|
hugetlb_cma_size_in_node[nid] = tmp;
|
|
hugetlb_cma_size += tmp;
|
|
|
|
/*
|
|
* Skip the separator if have one, otherwise
|
|
* break the parsing.
|
|
*/
|
|
if (*s == ',')
|
|
s++;
|
|
else
|
|
break;
|
|
} else {
|
|
hugetlb_cma_size = memparse(p, &p);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
early_param("hugetlb_cma", cmdline_parse_hugetlb_cma);
|
|
|
|
void __init hugetlb_cma_reserve(int order)
|
|
{
|
|
unsigned long size, reserved, per_node;
|
|
bool node_specific_cma_alloc = false;
|
|
int nid;
|
|
|
|
cma_reserve_called = true;
|
|
|
|
if (!hugetlb_cma_size)
|
|
return;
|
|
|
|
for (nid = 0; nid < MAX_NUMNODES; nid++) {
|
|
if (hugetlb_cma_size_in_node[nid] == 0)
|
|
continue;
|
|
|
|
if (!node_online(nid)) {
|
|
pr_warn("hugetlb_cma: invalid node %d specified\n", nid);
|
|
hugetlb_cma_size -= hugetlb_cma_size_in_node[nid];
|
|
hugetlb_cma_size_in_node[nid] = 0;
|
|
continue;
|
|
}
|
|
|
|
if (hugetlb_cma_size_in_node[nid] < (PAGE_SIZE << order)) {
|
|
pr_warn("hugetlb_cma: cma area of node %d should be at least %lu MiB\n",
|
|
nid, (PAGE_SIZE << order) / SZ_1M);
|
|
hugetlb_cma_size -= hugetlb_cma_size_in_node[nid];
|
|
hugetlb_cma_size_in_node[nid] = 0;
|
|
} else {
|
|
node_specific_cma_alloc = true;
|
|
}
|
|
}
|
|
|
|
/* Validate the CMA size again in case some invalid nodes specified. */
|
|
if (!hugetlb_cma_size)
|
|
return;
|
|
|
|
if (hugetlb_cma_size < (PAGE_SIZE << order)) {
|
|
pr_warn("hugetlb_cma: cma area should be at least %lu MiB\n",
|
|
(PAGE_SIZE << order) / SZ_1M);
|
|
hugetlb_cma_size = 0;
|
|
return;
|
|
}
|
|
|
|
if (!node_specific_cma_alloc) {
|
|
/*
|
|
* If 3 GB area is requested on a machine with 4 numa nodes,
|
|
* let's allocate 1 GB on first three nodes and ignore the last one.
|
|
*/
|
|
per_node = DIV_ROUND_UP(hugetlb_cma_size, nr_online_nodes);
|
|
pr_info("hugetlb_cma: reserve %lu MiB, up to %lu MiB per node\n",
|
|
hugetlb_cma_size / SZ_1M, per_node / SZ_1M);
|
|
}
|
|
|
|
reserved = 0;
|
|
for_each_online_node(nid) {
|
|
int res;
|
|
char name[CMA_MAX_NAME];
|
|
|
|
if (node_specific_cma_alloc) {
|
|
if (hugetlb_cma_size_in_node[nid] == 0)
|
|
continue;
|
|
|
|
size = hugetlb_cma_size_in_node[nid];
|
|
} else {
|
|
size = min(per_node, hugetlb_cma_size - reserved);
|
|
}
|
|
|
|
size = round_up(size, PAGE_SIZE << order);
|
|
|
|
snprintf(name, sizeof(name), "hugetlb%d", nid);
|
|
/*
|
|
* Note that 'order per bit' is based on smallest size that
|
|
* may be returned to CMA allocator in the case of
|
|
* huge page demotion.
|
|
*/
|
|
res = cma_declare_contiguous_nid(0, size, 0,
|
|
PAGE_SIZE << HUGETLB_PAGE_ORDER,
|
|
0, false, name,
|
|
&hugetlb_cma[nid], nid);
|
|
if (res) {
|
|
pr_warn("hugetlb_cma: reservation failed: err %d, node %d",
|
|
res, nid);
|
|
continue;
|
|
}
|
|
|
|
reserved += size;
|
|
pr_info("hugetlb_cma: reserved %lu MiB on node %d\n",
|
|
size / SZ_1M, nid);
|
|
|
|
if (reserved >= hugetlb_cma_size)
|
|
break;
|
|
}
|
|
|
|
if (!reserved)
|
|
/*
|
|
* hugetlb_cma_size is used to determine if allocations from
|
|
* cma are possible. Set to zero if no cma regions are set up.
|
|
*/
|
|
hugetlb_cma_size = 0;
|
|
}
|
|
|
|
void __init hugetlb_cma_check(void)
|
|
{
|
|
if (!hugetlb_cma_size || cma_reserve_called)
|
|
return;
|
|
|
|
pr_warn("hugetlb_cma: the option isn't supported by current arch\n");
|
|
}
|
|
|
|
#endif /* CONFIG_CMA */
|