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![Vaishali Thakkar](/assets/img/avatar_default.png)
Currently incorrect default hugepage pool size is reported by proc nr_hugepages when number of pages for the default huge page size is specified twice. When multiple huge page sizes are supported, /proc/sys/vm/nr_hugepages indicates the current number of pre-allocated huge pages of the default size. Basically /proc/sys/vm/nr_hugepages displays default_hstate-> max_huge_pages and after boot time pre-allocation, max_huge_pages should equal the number of pre-allocated pages (nr_hugepages). Test case: Note that this is specific to x86 architecture. Boot the kernel with command line option 'default_hugepagesz=1G hugepages=X hugepagesz=2M hugepages=Y hugepagesz=1G hugepages=Z'. After boot, 'cat /proc/sys/vm/nr_hugepages' and 'sysctl -a | grep hugepages' returns the value X. However, dmesg output shows that Z huge pages were pre-allocated. So, the root cause of the problem here is that the global variable default_hstate_max_huge_pages is set if a default huge page size is specified (directly or indirectly) on the command line. After the command line processing in hugetlb_init, if default_hstate_max_huge_pages is set, the value is assigned to default_hstae.max_huge_pages. However, default_hstate.max_huge_pages may have already been set based on the number of pre-allocated huge pages of default_hstate size. The solution to this problem is if hstate->max_huge_pages is already set then it should not set as a result of global max_huge_pages value. Basically if the value of the variable hugepages is set multiple times on a command line for a specific supported hugepagesize then proc layer should consider the last specified value. Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
4407 lines
118 KiB
C
4407 lines
118 KiB
C
/*
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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/bootmem.h>
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#include <linux/sysfs.h>
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#include <linux/slab.h>
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#include <linux/rmap.h>
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#include <linux/swap.h>
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#include <linux/swapops.h>
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#include <linux/page-isolation.h>
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#include <linux/jhash.h>
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#include <asm/page.h>
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#include <asm/pgtable.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 "internal.h"
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int hugepages_treat_as_movable;
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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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/*
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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 unsigned long __initdata default_hstate_size;
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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 void unlock_or_release_subpool(struct hugepage_subpool *spool)
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{
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bool free = (spool->count == 0) && (spool->used_hpages == 0);
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spin_unlock(&spool->lock);
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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 mased on minimum size and
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* free the subpool */
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if (free) {
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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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spin_lock(&spool->lock);
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BUG_ON(!spool->count);
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spool->count--;
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unlock_or_release_subpool(spool);
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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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* the 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 manitained.
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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(&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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if (spool->min_hpages != -1) { /* minimum size accounting */
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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(&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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if (!spool)
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return delta;
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spin_lock(&spool->lock);
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if (spool->max_hpages != -1) /* maximum size accounting */
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spool->used_hpages -= delta;
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if (spool->min_hpages != -1) { /* minimum size accounting */
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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);
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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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/*
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* Region tracking -- allows tracking of reservations and instantiated pages
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* across the pages in a mapping.
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*
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* The region data structures are embedded into a resv_map and protected
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* by a resv_map's lock. The set of regions within the resv_map represent
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* reservations for huge pages, or huge pages that have already been
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* instantiated within the map. The from and to elements are huge page
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* indicies into the associated mapping. from indicates the starting index
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* of the region. to represents the first index past the end of the region.
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*
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* For example, a file region structure with from == 0 and to == 4 represents
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* four huge pages in a mapping. It is important to note that the to element
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* represents the first element past the end of the region. This is used in
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* arithmetic as 4(to) - 0(from) = 4 huge pages in the region.
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*
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* Interval notation of the form [from, to) will be used to indicate that
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* the endpoint from is inclusive and to is exclusive.
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*/
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struct file_region {
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struct list_head link;
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long from;
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long to;
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};
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/*
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* Add the huge page range represented by [f, t) to the reserve
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* map. In the normal case, existing regions will be expanded
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* to accommodate the specified range. Sufficient regions should
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* exist for expansion due to the previous call to region_chg
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* with the same range. However, it is possible that region_del
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* could have been called after region_chg and modifed the map
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* in such a way that no region exists to be expanded. In this
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* case, pull a region descriptor from the cache associated with
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* the map and use that for the new range.
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*
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* Return the number of new huge pages added to the map. This
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* number is greater than or equal to zero.
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*/
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static long region_add(struct resv_map *resv, long f, long t)
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{
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struct list_head *head = &resv->regions;
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struct file_region *rg, *nrg, *trg;
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long add = 0;
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spin_lock(&resv->lock);
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/* Locate the region we are either in or before. */
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list_for_each_entry(rg, head, link)
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if (f <= rg->to)
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break;
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/*
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* If no region exists which can be expanded to include the
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* specified range, the list must have been modified by an
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* interleving call to region_del(). Pull a region descriptor
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* from the cache and use it for this range.
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*/
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if (&rg->link == head || t < rg->from) {
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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,
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link);
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list_del(&nrg->link);
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nrg->from = f;
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nrg->to = t;
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list_add(&nrg->link, rg->link.prev);
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add += t - f;
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goto out_locked;
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}
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/* Round our left edge to the current segment if it encloses us. */
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if (f > rg->from)
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f = rg->from;
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/* Check for and consume any regions we now overlap with. */
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nrg = rg;
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list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
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if (&rg->link == head)
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break;
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if (rg->from > t)
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break;
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/* If this area reaches higher then extend our area to
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* include it completely. If this is not the first area
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* which we intend to reuse, free it. */
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if (rg->to > t)
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t = rg->to;
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if (rg != nrg) {
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/* Decrement return value by the deleted range.
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* Another range will span this area so that by
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* end of routine add will be >= zero
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*/
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add -= (rg->to - rg->from);
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list_del(&rg->link);
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kfree(rg);
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}
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}
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add += (nrg->from - f); /* Added to beginning of region */
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nrg->from = f;
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add += t - nrg->to; /* Added to end of region */
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nrg->to = t;
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out_locked:
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resv->adds_in_progress--;
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spin_unlock(&resv->lock);
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VM_BUG_ON(add < 0);
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return add;
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}
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/*
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* Examine the existing reserve map and determine how many
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* huge pages in the specified range [f, t) are NOT currently
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* represented. This routine is called before a subsequent
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* call to region_add that will actually modify the reserve
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* map to add the specified range [f, t). region_chg does
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* not change the number of huge pages represented by the
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* map. However, if the existing regions in the map can not
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* be expanded to represent the new range, a new file_region
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* structure is added to the map as a placeholder. This is
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* so that the subsequent region_add call will have all the
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* regions it needs and will not fail.
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*
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* Upon entry, region_chg will also examine the cache of region descriptors
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* associated with the map. If there are not enough descriptors cached, one
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* will be allocated for the in progress add operation.
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*
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* Returns the number of huge pages that need to be added to the existing
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* reservation map for the range [f, t). This number is greater or equal to
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* zero. -ENOMEM is returned if a new file_region structure or cache entry
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* is needed and can not be allocated.
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*/
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static long region_chg(struct resv_map *resv, long f, long t)
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{
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struct list_head *head = &resv->regions;
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struct file_region *rg, *nrg = NULL;
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long chg = 0;
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retry:
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spin_lock(&resv->lock);
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retry_locked:
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resv->adds_in_progress++;
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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.
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*/
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if (resv->adds_in_progress > resv->region_cache_count) {
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struct file_region *trg;
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VM_BUG_ON(resv->adds_in_progress - resv->region_cache_count > 1);
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/* Must drop lock to allocate a new descriptor. */
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resv->adds_in_progress--;
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spin_unlock(&resv->lock);
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trg = kmalloc(sizeof(*trg), GFP_KERNEL);
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if (!trg) {
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kfree(nrg);
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return -ENOMEM;
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}
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spin_lock(&resv->lock);
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list_add(&trg->link, &resv->region_cache);
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resv->region_cache_count++;
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goto retry_locked;
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}
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/* Locate the region we are before or in. */
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list_for_each_entry(rg, head, link)
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if (f <= rg->to)
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break;
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/* If we are below the current region then a new region is required.
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* Subtle, allocate a new region at the position but make it zero
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* size such that we can guarantee to record the reservation. */
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if (&rg->link == head || t < rg->from) {
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if (!nrg) {
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resv->adds_in_progress--;
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spin_unlock(&resv->lock);
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nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
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if (!nrg)
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return -ENOMEM;
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nrg->from = f;
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nrg->to = f;
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INIT_LIST_HEAD(&nrg->link);
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goto retry;
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}
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list_add(&nrg->link, rg->link.prev);
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chg = t - f;
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goto out_nrg;
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}
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/* Round our left edge to the current segment if it encloses us. */
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if (f > rg->from)
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f = rg->from;
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chg = t - f;
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/* Check for and consume any regions we now overlap with. */
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list_for_each_entry(rg, rg->link.prev, link) {
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if (&rg->link == head)
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break;
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if (rg->from > t)
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goto out;
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/* We overlap with this area, if it extends further than
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* us then we must extend ourselves. Account for its
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* existing reservation. */
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if (rg->to > t) {
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chg += rg->to - t;
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t = rg->to;
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}
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chg -= rg->to - rg->from;
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}
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out:
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spin_unlock(&resv->lock);
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/* We already know we raced and no longer need the new region */
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kfree(nrg);
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return chg;
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out_nrg:
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spin_unlock(&resv->lock);
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return chg;
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}
|
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|
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/*
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* Abort the in progress add operation. The adds_in_progress field
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* of the resv_map keeps track of the operations in progress between
|
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* calls to region_chg and region_add. Operations are sometimes
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* aborted after the call to region_chg. In such cases, region_abort
|
|
* is called to decrement the adds_in_progress counter.
|
|
*
|
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* 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
|
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* arguments will match the associated region_chg call.
|
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*/
|
|
static void region_abort(struct resv_map *resv, long f, long t)
|
|
{
|
|
spin_lock(&resv->lock);
|
|
VM_BUG_ON(!resv->region_cache_count);
|
|
resv->adds_in_progress--;
|
|
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;
|
|
|
|
/* New entry for end of split region */
|
|
nrg->from = t;
|
|
nrg->to = rg->to;
|
|
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;
|
|
list_del(&rg->link);
|
|
kfree(rg);
|
|
continue;
|
|
}
|
|
|
|
if (f <= rg->from) { /* Trim beginning of region */
|
|
del += t - rg->from;
|
|
rg->from = t;
|
|
} else { /* Trim end of region */
|
|
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, bool restore_reserve)
|
|
{
|
|
struct hugepage_subpool *spool = subpool_inode(inode);
|
|
long rsv_adjust;
|
|
|
|
rsv_adjust = hugepage_subpool_get_pages(spool, 1);
|
|
if (restore_reserve && rsv_adjust) {
|
|
struct hstate *h = hstate_inode(inode);
|
|
|
|
hugetlb_acct_memory(h, 1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct hstate *hstate;
|
|
|
|
if (!is_vm_hugetlb_page(vma))
|
|
return PAGE_SIZE;
|
|
|
|
hstate = hstate_vma(vma);
|
|
|
|
return 1UL << huge_page_shift(hstate);
|
|
}
|
|
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 version of this
|
|
* function is required.
|
|
*/
|
|
#ifndef vma_mmu_pagesize
|
|
unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
|
|
{
|
|
return vma_kernel_pagesize(vma);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
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;
|
|
|
|
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)
|
|
{
|
|
return inode->i_mapping->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;
|
|
}
|
|
|
|
/* 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 reverves 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))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
static void enqueue_huge_page(struct hstate *h, struct page *page)
|
|
{
|
|
int nid = page_to_nid(page);
|
|
list_move(&page->lru, &h->hugepage_freelists[nid]);
|
|
h->free_huge_pages++;
|
|
h->free_huge_pages_node[nid]++;
|
|
}
|
|
|
|
static struct page *dequeue_huge_page_node(struct hstate *h, int nid)
|
|
{
|
|
struct page *page;
|
|
|
|
list_for_each_entry(page, &h->hugepage_freelists[nid], lru)
|
|
if (!is_migrate_isolate_page(page))
|
|
break;
|
|
/*
|
|
* if 'non-isolated free hugepage' not found on the list,
|
|
* the allocation fails.
|
|
*/
|
|
if (&h->hugepage_freelists[nid] == &page->lru)
|
|
return NULL;
|
|
list_move(&page->lru, &h->hugepage_activelist);
|
|
set_page_refcounted(page);
|
|
h->free_huge_pages--;
|
|
h->free_huge_pages_node[nid]--;
|
|
return page;
|
|
}
|
|
|
|
/* Movability of hugepages depends on migration support. */
|
|
static inline gfp_t htlb_alloc_mask(struct hstate *h)
|
|
{
|
|
if (hugepages_treat_as_movable || hugepage_migration_supported(h))
|
|
return GFP_HIGHUSER_MOVABLE;
|
|
else
|
|
return GFP_HIGHUSER;
|
|
}
|
|
|
|
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;
|
|
nodemask_t *nodemask;
|
|
struct zonelist *zonelist;
|
|
struct zone *zone;
|
|
struct zoneref *z;
|
|
unsigned int cpuset_mems_cookie;
|
|
|
|
/*
|
|
* 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;
|
|
|
|
retry_cpuset:
|
|
cpuset_mems_cookie = read_mems_allowed_begin();
|
|
zonelist = huge_zonelist(vma, address,
|
|
htlb_alloc_mask(h), &mpol, &nodemask);
|
|
|
|
for_each_zone_zonelist_nodemask(zone, z, zonelist,
|
|
MAX_NR_ZONES - 1, nodemask) {
|
|
if (cpuset_zone_allowed(zone, htlb_alloc_mask(h))) {
|
|
page = dequeue_huge_page_node(h, zone_to_nid(zone));
|
|
if (page) {
|
|
if (avoid_reserve)
|
|
break;
|
|
if (!vma_has_reserves(vma, chg))
|
|
break;
|
|
|
|
SetPagePrivate(page);
|
|
h->resv_huge_pages--;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
mpol_cond_put(mpol);
|
|
if (unlikely(!page && read_mems_allowed_retry(cpuset_mems_cookie)))
|
|
goto retry_cpuset;
|
|
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(nid, *nodes_allowed);
|
|
if (nid == MAX_NUMNODES)
|
|
nid = first_node(*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 free_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--)
|
|
|
|
#if defined(CONFIG_X86_64) && ((defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA))
|
|
static void destroy_compound_gigantic_page(struct page *page,
|
|
unsigned int order)
|
|
{
|
|
int i;
|
|
int nr_pages = 1 << order;
|
|
struct page *p = page + 1;
|
|
|
|
for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
|
|
clear_compound_head(p);
|
|
set_page_refcounted(p);
|
|
}
|
|
|
|
set_compound_order(page, 0);
|
|
__ClearPageHead(page);
|
|
}
|
|
|
|
static void free_gigantic_page(struct page *page, unsigned int order)
|
|
{
|
|
free_contig_range(page_to_pfn(page), 1 << order);
|
|
}
|
|
|
|
static int __alloc_gigantic_page(unsigned long start_pfn,
|
|
unsigned long nr_pages)
|
|
{
|
|
unsigned long end_pfn = start_pfn + nr_pages;
|
|
return alloc_contig_range(start_pfn, end_pfn, MIGRATE_MOVABLE);
|
|
}
|
|
|
|
static bool pfn_range_valid_gigantic(unsigned long start_pfn,
|
|
unsigned long nr_pages)
|
|
{
|
|
unsigned long i, end_pfn = start_pfn + nr_pages;
|
|
struct page *page;
|
|
|
|
for (i = start_pfn; i < end_pfn; i++) {
|
|
if (!pfn_valid(i))
|
|
return false;
|
|
|
|
page = pfn_to_page(i);
|
|
|
|
if (PageReserved(page))
|
|
return false;
|
|
|
|
if (page_count(page) > 0)
|
|
return false;
|
|
|
|
if (PageHuge(page))
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool zone_spans_last_pfn(const struct zone *zone,
|
|
unsigned long start_pfn, unsigned long nr_pages)
|
|
{
|
|
unsigned long last_pfn = start_pfn + nr_pages - 1;
|
|
return zone_spans_pfn(zone, last_pfn);
|
|
}
|
|
|
|
static struct page *alloc_gigantic_page(int nid, unsigned int order)
|
|
{
|
|
unsigned long nr_pages = 1 << order;
|
|
unsigned long ret, pfn, flags;
|
|
struct zone *z;
|
|
|
|
z = NODE_DATA(nid)->node_zones;
|
|
for (; z - NODE_DATA(nid)->node_zones < MAX_NR_ZONES; z++) {
|
|
spin_lock_irqsave(&z->lock, flags);
|
|
|
|
pfn = ALIGN(z->zone_start_pfn, nr_pages);
|
|
while (zone_spans_last_pfn(z, pfn, nr_pages)) {
|
|
if (pfn_range_valid_gigantic(pfn, nr_pages)) {
|
|
/*
|
|
* We release the zone lock here because
|
|
* alloc_contig_range() will also lock the zone
|
|
* at some point. If there's an allocation
|
|
* spinning on this lock, it may win the race
|
|
* and cause alloc_contig_range() to fail...
|
|
*/
|
|
spin_unlock_irqrestore(&z->lock, flags);
|
|
ret = __alloc_gigantic_page(pfn, nr_pages);
|
|
if (!ret)
|
|
return pfn_to_page(pfn);
|
|
spin_lock_irqsave(&z->lock, flags);
|
|
}
|
|
pfn += nr_pages;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&z->lock, flags);
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void prep_new_huge_page(struct hstate *h, struct page *page, int nid);
|
|
static void prep_compound_gigantic_page(struct page *page, unsigned int order);
|
|
|
|
static struct page *alloc_fresh_gigantic_page_node(struct hstate *h, int nid)
|
|
{
|
|
struct page *page;
|
|
|
|
page = alloc_gigantic_page(nid, huge_page_order(h));
|
|
if (page) {
|
|
prep_compound_gigantic_page(page, huge_page_order(h));
|
|
prep_new_huge_page(h, page, nid);
|
|
}
|
|
|
|
return page;
|
|
}
|
|
|
|
static int alloc_fresh_gigantic_page(struct hstate *h,
|
|
nodemask_t *nodes_allowed)
|
|
{
|
|
struct page *page = NULL;
|
|
int nr_nodes, node;
|
|
|
|
for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
|
|
page = alloc_fresh_gigantic_page_node(h, node);
|
|
if (page)
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline bool gigantic_page_supported(void) { return true; }
|
|
#else
|
|
static inline bool gigantic_page_supported(void) { return false; }
|
|
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) { }
|
|
static inline int alloc_fresh_gigantic_page(struct hstate *h,
|
|
nodemask_t *nodes_allowed) { return 0; }
|
|
#endif
|
|
|
|
static void update_and_free_page(struct hstate *h, struct page *page)
|
|
{
|
|
int i;
|
|
|
|
if (hstate_is_gigantic(h) && !gigantic_page_supported())
|
|
return;
|
|
|
|
h->nr_huge_pages--;
|
|
h->nr_huge_pages_node[page_to_nid(page)]--;
|
|
for (i = 0; i < pages_per_huge_page(h); i++) {
|
|
page[i].flags &= ~(1 << PG_locked | 1 << PG_error |
|
|
1 << PG_referenced | 1 << PG_dirty |
|
|
1 << PG_active | 1 << PG_private |
|
|
1 << PG_writeback);
|
|
}
|
|
VM_BUG_ON_PAGE(hugetlb_cgroup_from_page(page), page);
|
|
set_compound_page_dtor(page, NULL_COMPOUND_DTOR);
|
|
set_page_refcounted(page);
|
|
if (hstate_is_gigantic(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));
|
|
}
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Test to determine whether the hugepage is "active/in-use" (i.e. being linked
|
|
* to hstate->hugepage_activelist.)
|
|
*
|
|
* This function can be called for tail pages, but never returns true for them.
|
|
*/
|
|
bool page_huge_active(struct page *page)
|
|
{
|
|
VM_BUG_ON_PAGE(!PageHuge(page), page);
|
|
return PageHead(page) && PagePrivate(&page[1]);
|
|
}
|
|
|
|
/* never called for tail page */
|
|
static void set_page_huge_active(struct page *page)
|
|
{
|
|
VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
|
|
SetPagePrivate(&page[1]);
|
|
}
|
|
|
|
static void clear_page_huge_active(struct page *page)
|
|
{
|
|
VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
|
|
ClearPagePrivate(&page[1]);
|
|
}
|
|
|
|
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 =
|
|
(struct hugepage_subpool *)page_private(page);
|
|
bool restore_reserve;
|
|
|
|
set_page_private(page, 0);
|
|
page->mapping = NULL;
|
|
VM_BUG_ON_PAGE(page_count(page), page);
|
|
VM_BUG_ON_PAGE(page_mapcount(page), page);
|
|
restore_reserve = PagePrivate(page);
|
|
ClearPagePrivate(page);
|
|
|
|
/*
|
|
* 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(&hugetlb_lock);
|
|
clear_page_huge_active(page);
|
|
hugetlb_cgroup_uncharge_page(hstate_index(h),
|
|
pages_per_huge_page(h), page);
|
|
if (restore_reserve)
|
|
h->resv_huge_pages++;
|
|
|
|
if (h->surplus_huge_pages_node[nid]) {
|
|
/* remove the page from active list */
|
|
list_del(&page->lru);
|
|
update_and_free_page(h, page);
|
|
h->surplus_huge_pages--;
|
|
h->surplus_huge_pages_node[nid]--;
|
|
} else {
|
|
arch_clear_hugepage_flags(page);
|
|
enqueue_huge_page(h, page);
|
|
}
|
|
spin_unlock(&hugetlb_lock);
|
|
}
|
|
|
|
static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
|
|
{
|
|
INIT_LIST_HEAD(&page->lru);
|
|
set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);
|
|
spin_lock(&hugetlb_lock);
|
|
set_hugetlb_cgroup(page, NULL);
|
|
h->nr_huge_pages++;
|
|
h->nr_huge_pages_node[nid]++;
|
|
spin_unlock(&hugetlb_lock);
|
|
put_page(page); /* free it into the hugepage allocator */
|
|
}
|
|
|
|
static void prep_compound_gigantic_page(struct page *page, unsigned int order)
|
|
{
|
|
int i;
|
|
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. Otherwse 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);
|
|
set_page_count(p, 0);
|
|
set_compound_head(p, page);
|
|
}
|
|
atomic_set(compound_mapcount_ptr(page), -1);
|
|
}
|
|
|
|
/*
|
|
* 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 get_compound_page_dtor(page_head) == free_huge_page;
|
|
}
|
|
|
|
pgoff_t __basepage_index(struct page *page)
|
|
{
|
|
struct page *page_head = compound_head(page);
|
|
pgoff_t index = page_index(page_head);
|
|
unsigned long compound_idx;
|
|
|
|
if (!PageHuge(page_head))
|
|
return page_index(page);
|
|
|
|
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_fresh_huge_page_node(struct hstate *h, int nid)
|
|
{
|
|
struct page *page;
|
|
|
|
page = __alloc_pages_node(nid,
|
|
htlb_alloc_mask(h)|__GFP_COMP|__GFP_THISNODE|
|
|
__GFP_REPEAT|__GFP_NOWARN,
|
|
huge_page_order(h));
|
|
if (page) {
|
|
prep_new_huge_page(h, page, nid);
|
|
}
|
|
|
|
return page;
|
|
}
|
|
|
|
static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed)
|
|
{
|
|
struct page *page;
|
|
int nr_nodes, node;
|
|
int ret = 0;
|
|
|
|
for_each_node_mask_to_alloc(h, nr_nodes, node, nodes_allowed) {
|
|
page = alloc_fresh_huge_page_node(h, node);
|
|
if (page) {
|
|
ret = 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (ret)
|
|
count_vm_event(HTLB_BUDDY_PGALLOC);
|
|
else
|
|
count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Free huge page from pool from next node to free.
|
|
* Attempt to keep persistent huge pages more or less
|
|
* balanced over allowed nodes.
|
|
* Called with hugetlb_lock locked.
|
|
*/
|
|
static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed,
|
|
bool acct_surplus)
|
|
{
|
|
int nr_nodes, node;
|
|
int ret = 0;
|
|
|
|
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])) {
|
|
struct page *page =
|
|
list_entry(h->hugepage_freelists[node].next,
|
|
struct page, lru);
|
|
list_del(&page->lru);
|
|
h->free_huge_pages--;
|
|
h->free_huge_pages_node[node]--;
|
|
if (acct_surplus) {
|
|
h->surplus_huge_pages--;
|
|
h->surplus_huge_pages_node[node]--;
|
|
}
|
|
update_and_free_page(h, page);
|
|
ret = 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Dissolve a given free hugepage into free buddy pages. This function does
|
|
* nothing for in-use (including surplus) hugepages.
|
|
*/
|
|
static void dissolve_free_huge_page(struct page *page)
|
|
{
|
|
spin_lock(&hugetlb_lock);
|
|
if (PageHuge(page) && !page_count(page)) {
|
|
struct hstate *h = page_hstate(page);
|
|
int nid = page_to_nid(page);
|
|
list_del(&page->lru);
|
|
h->free_huge_pages--;
|
|
h->free_huge_pages_node[nid]--;
|
|
update_and_free_page(h, page);
|
|
}
|
|
spin_unlock(&hugetlb_lock);
|
|
}
|
|
|
|
/*
|
|
* Dissolve free hugepages in a given pfn range. Used by memory hotplug to
|
|
* make specified memory blocks removable from the system.
|
|
* Note that start_pfn should aligned with (minimum) hugepage size.
|
|
*/
|
|
void dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn)
|
|
{
|
|
unsigned long pfn;
|
|
|
|
if (!hugepages_supported())
|
|
return;
|
|
|
|
VM_BUG_ON(!IS_ALIGNED(start_pfn, 1 << minimum_order));
|
|
for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << minimum_order)
|
|
dissolve_free_huge_page(pfn_to_page(pfn));
|
|
}
|
|
|
|
/*
|
|
* There are 3 ways this can get called:
|
|
* 1. With vma+addr: we use the VMA's memory policy
|
|
* 2. With !vma, but nid=NUMA_NO_NODE: We try to allocate a huge
|
|
* page from any node, and let the buddy allocator itself figure
|
|
* it out.
|
|
* 3. With !vma, but nid!=NUMA_NO_NODE. We allocate a huge page
|
|
* strictly from 'nid'
|
|
*/
|
|
static struct page *__hugetlb_alloc_buddy_huge_page(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long addr, int nid)
|
|
{
|
|
int order = huge_page_order(h);
|
|
gfp_t gfp = htlb_alloc_mask(h)|__GFP_COMP|__GFP_REPEAT|__GFP_NOWARN;
|
|
unsigned int cpuset_mems_cookie;
|
|
|
|
/*
|
|
* We need a VMA to get a memory policy. If we do not
|
|
* have one, we use the 'nid' argument.
|
|
*
|
|
* The mempolicy stuff below has some non-inlined bits
|
|
* and calls ->vm_ops. That makes it hard to optimize at
|
|
* compile-time, even when NUMA is off and it does
|
|
* nothing. This helps the compiler optimize it out.
|
|
*/
|
|
if (!IS_ENABLED(CONFIG_NUMA) || !vma) {
|
|
/*
|
|
* If a specific node is requested, make sure to
|
|
* get memory from there, but only when a node
|
|
* is explicitly specified.
|
|
*/
|
|
if (nid != NUMA_NO_NODE)
|
|
gfp |= __GFP_THISNODE;
|
|
/*
|
|
* Make sure to call something that can handle
|
|
* nid=NUMA_NO_NODE
|
|
*/
|
|
return alloc_pages_node(nid, gfp, order);
|
|
}
|
|
|
|
/*
|
|
* OK, so we have a VMA. Fetch the mempolicy and try to
|
|
* allocate a huge page with it. We will only reach this
|
|
* when CONFIG_NUMA=y.
|
|
*/
|
|
do {
|
|
struct page *page;
|
|
struct mempolicy *mpol;
|
|
struct zonelist *zl;
|
|
nodemask_t *nodemask;
|
|
|
|
cpuset_mems_cookie = read_mems_allowed_begin();
|
|
zl = huge_zonelist(vma, addr, gfp, &mpol, &nodemask);
|
|
mpol_cond_put(mpol);
|
|
page = __alloc_pages_nodemask(gfp, order, zl, nodemask);
|
|
if (page)
|
|
return page;
|
|
} while (read_mems_allowed_retry(cpuset_mems_cookie));
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* There are two ways to allocate a huge page:
|
|
* 1. When you have a VMA and an address (like a fault)
|
|
* 2. When you have no VMA (like when setting /proc/.../nr_hugepages)
|
|
*
|
|
* 'vma' and 'addr' are only for (1). 'nid' is always NUMA_NO_NODE in
|
|
* this case which signifies that the allocation should be done with
|
|
* respect for the VMA's memory policy.
|
|
*
|
|
* For (2), we ignore 'vma' and 'addr' and use 'nid' exclusively. This
|
|
* implies that memory policies will not be taken in to account.
|
|
*/
|
|
static struct page *__alloc_buddy_huge_page(struct hstate *h,
|
|
struct vm_area_struct *vma, unsigned long addr, int nid)
|
|
{
|
|
struct page *page;
|
|
unsigned int r_nid;
|
|
|
|
if (hstate_is_gigantic(h))
|
|
return NULL;
|
|
|
|
/*
|
|
* Make sure that anyone specifying 'nid' is not also specifying a VMA.
|
|
* This makes sure the caller is picking _one_ of the modes with which
|
|
* we can call this function, not both.
|
|
*/
|
|
if (vma || (addr != -1)) {
|
|
VM_WARN_ON_ONCE(addr == -1);
|
|
VM_WARN_ON_ONCE(nid != NUMA_NO_NODE);
|
|
}
|
|
/*
|
|
* Assume we will successfully allocate the surplus page to
|
|
* prevent racing processes from causing the surplus to exceed
|
|
* overcommit
|
|
*
|
|
* This however introduces a different race, where a process B
|
|
* tries to grow the static hugepage pool while alloc_pages() is
|
|
* called by process A. B will only examine the per-node
|
|
* counters in determining if surplus huge pages can be
|
|
* converted to normal huge pages in adjust_pool_surplus(). A
|
|
* won't be able to increment the per-node counter, until the
|
|
* lock is dropped by B, but B doesn't drop hugetlb_lock until
|
|
* no more huge pages can be converted from surplus to normal
|
|
* state (and doesn't try to convert again). Thus, we have a
|
|
* case where a surplus huge page exists, the pool is grown, and
|
|
* the surplus huge page still exists after, even though it
|
|
* should just have been converted to a normal huge page. This
|
|
* does not leak memory, though, as the hugepage will be freed
|
|
* once it is out of use. It also does not allow the counters to
|
|
* go out of whack in adjust_pool_surplus() as we don't modify
|
|
* the node values until we've gotten the hugepage and only the
|
|
* per-node value is checked there.
|
|
*/
|
|
spin_lock(&hugetlb_lock);
|
|
if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
|
|
spin_unlock(&hugetlb_lock);
|
|
return NULL;
|
|
} else {
|
|
h->nr_huge_pages++;
|
|
h->surplus_huge_pages++;
|
|
}
|
|
spin_unlock(&hugetlb_lock);
|
|
|
|
page = __hugetlb_alloc_buddy_huge_page(h, vma, addr, nid);
|
|
|
|
spin_lock(&hugetlb_lock);
|
|
if (page) {
|
|
INIT_LIST_HEAD(&page->lru);
|
|
r_nid = page_to_nid(page);
|
|
set_compound_page_dtor(page, HUGETLB_PAGE_DTOR);
|
|
set_hugetlb_cgroup(page, NULL);
|
|
/*
|
|
* We incremented the global counters already
|
|
*/
|
|
h->nr_huge_pages_node[r_nid]++;
|
|
h->surplus_huge_pages_node[r_nid]++;
|
|
__count_vm_event(HTLB_BUDDY_PGALLOC);
|
|
} else {
|
|
h->nr_huge_pages--;
|
|
h->surplus_huge_pages--;
|
|
__count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
|
|
}
|
|
spin_unlock(&hugetlb_lock);
|
|
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Allocate a huge page from 'nid'. Note, 'nid' may be
|
|
* NUMA_NO_NODE, which means that it may be allocated
|
|
* anywhere.
|
|
*/
|
|
static
|
|
struct page *__alloc_buddy_huge_page_no_mpol(struct hstate *h, int nid)
|
|
{
|
|
unsigned long addr = -1;
|
|
|
|
return __alloc_buddy_huge_page(h, NULL, addr, nid);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
return __alloc_buddy_huge_page(h, vma, addr, NUMA_NO_NODE);
|
|
}
|
|
|
|
/*
|
|
* This allocation function is useful in the context where vma is irrelevant.
|
|
* E.g. soft-offlining uses this function because it only cares physical
|
|
* address of error page.
|
|
*/
|
|
struct page *alloc_huge_page_node(struct hstate *h, int nid)
|
|
{
|
|
struct page *page = NULL;
|
|
|
|
spin_lock(&hugetlb_lock);
|
|
if (h->free_huge_pages - h->resv_huge_pages > 0)
|
|
page = dequeue_huge_page_node(h, nid);
|
|
spin_unlock(&hugetlb_lock);
|
|
|
|
if (!page)
|
|
page = __alloc_buddy_huge_page_no_mpol(h, nid);
|
|
|
|
return page;
|
|
}
|
|
|
|
/*
|
|
* Increase the hugetlb pool such that it can accommodate a reservation
|
|
* of size 'delta'.
|
|
*/
|
|
static int gather_surplus_pages(struct hstate *h, int delta)
|
|
{
|
|
struct list_head surplus_list;
|
|
struct page *page, *tmp;
|
|
int ret, i;
|
|
int needed, allocated;
|
|
bool alloc_ok = true;
|
|
|
|
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(&hugetlb_lock);
|
|
for (i = 0; i < needed; i++) {
|
|
page = __alloc_buddy_huge_page_no_mpol(h, NUMA_NO_NODE);
|
|
if (!page) {
|
|
alloc_ok = false;
|
|
break;
|
|
}
|
|
list_add(&page->lru, &surplus_list);
|
|
}
|
|
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(&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;
|
|
/*
|
|
* This page is now managed by the hugetlb allocator and has
|
|
* no users -- drop the buddy allocator's reference.
|
|
*/
|
|
put_page_testzero(page);
|
|
VM_BUG_ON_PAGE(page_count(page), page);
|
|
enqueue_huge_page(h, page);
|
|
}
|
|
free:
|
|
spin_unlock(&hugetlb_lock);
|
|
|
|
/* Free unnecessary surplus pages to the buddy allocator */
|
|
list_for_each_entry_safe(page, tmp, &surplus_list, lru)
|
|
put_page(page);
|
|
spin_lock(&hugetlb_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* When releasing a hugetlb pool reservation, any surplus pages that were
|
|
* allocated to satisfy the reservation must be explicitly freed if they were
|
|
* never used.
|
|
* Called with hugetlb_lock held.
|
|
*/
|
|
static void return_unused_surplus_pages(struct hstate *h,
|
|
unsigned long unused_resv_pages)
|
|
{
|
|
unsigned long nr_pages;
|
|
|
|
/* Uncommit the reservation */
|
|
h->resv_huge_pages -= unused_resv_pages;
|
|
|
|
/* Cannot return gigantic pages currently */
|
|
if (hstate_is_gigantic(h))
|
|
return;
|
|
|
|
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.
|
|
* free_pool_huge_page() will balance the the freed pages across the
|
|
* on-line nodes with memory and will handle the hstate accounting.
|
|
*/
|
|
while (nr_pages--) {
|
|
if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1))
|
|
break;
|
|
cond_resched_lock(&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.
|
|
*/
|
|
enum vma_resv_mode {
|
|
VMA_NEEDS_RESV,
|
|
VMA_COMMIT_RESV,
|
|
VMA_END_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;
|
|
|
|
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);
|
|
break;
|
|
case VMA_COMMIT_RESV:
|
|
ret = region_add(resv, idx, idx + 1);
|
|
break;
|
|
case VMA_END_RESV:
|
|
region_abort(resv, idx, idx + 1);
|
|
ret = 0;
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
|
|
if (vma->vm_flags & VM_MAYSHARE)
|
|
return ret;
|
|
else
|
|
return ret < 0 ? ret : 0;
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
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;
|
|
|
|
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;
|
|
}
|
|
|
|
ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg);
|
|
if (ret)
|
|
goto out_subpool_put;
|
|
|
|
spin_lock(&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(&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)) {
|
|
SetPagePrivate(page);
|
|
h->resv_huge_pages--;
|
|
}
|
|
spin_lock(&hugetlb_lock);
|
|
list_move(&page->lru, &h->hugepage_activelist);
|
|
/* Fall through */
|
|
}
|
|
hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, page);
|
|
spin_unlock(&hugetlb_lock);
|
|
|
|
set_page_private(page, (unsigned long)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);
|
|
}
|
|
return page;
|
|
|
|
out_uncharge_cgroup:
|
|
hugetlb_cgroup_uncharge_cgroup(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);
|
|
}
|
|
|
|
/*
|
|
* alloc_huge_page()'s wrapper which simply returns the page if allocation
|
|
* succeeds, otherwise NULL. This function is called from new_vma_page(),
|
|
* where no ERR_VALUE is expected to be returned.
|
|
*/
|
|
struct page *alloc_huge_page_noerr(struct vm_area_struct *vma,
|
|
unsigned long addr, int avoid_reserve)
|
|
{
|
|
struct page *page = alloc_huge_page(vma, addr, avoid_reserve);
|
|
if (IS_ERR(page))
|
|
page = NULL;
|
|
return page;
|
|
}
|
|
|
|
int __weak alloc_bootmem_huge_page(struct hstate *h)
|
|
{
|
|
struct huge_bootmem_page *m;
|
|
int nr_nodes, node;
|
|
|
|
for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
|
|
void *addr;
|
|
|
|
addr = memblock_virt_alloc_try_nid_nopanic(
|
|
huge_page_size(h), huge_page_size(h),
|
|
0, BOOTMEM_ALLOC_ACCESSIBLE, node);
|
|
if (addr) {
|
|
/*
|
|
* Use the beginning of the huge page to store the
|
|
* huge_bootmem_page struct (until gather_bootmem
|
|
* puts them into the mem_map).
|
|
*/
|
|
m = addr;
|
|
goto found;
|
|
}
|
|
}
|
|
return 0;
|
|
|
|
found:
|
|
BUG_ON(!IS_ALIGNED(virt_to_phys(m), huge_page_size(h)));
|
|
/* Put them into a private list first because mem_map is not up yet */
|
|
list_add(&m->list, &huge_boot_pages);
|
|
m->hstate = h;
|
|
return 1;
|
|
}
|
|
|
|
static void __init prep_compound_huge_page(struct page *page,
|
|
unsigned int order)
|
|
{
|
|
if (unlikely(order > (MAX_ORDER - 1)))
|
|
prep_compound_gigantic_page(page, order);
|
|
else
|
|
prep_compound_page(page, order);
|
|
}
|
|
|
|
/* Put bootmem huge pages into the standard lists after mem_map is up */
|
|
static void __init gather_bootmem_prealloc(void)
|
|
{
|
|
struct huge_bootmem_page *m;
|
|
|
|
list_for_each_entry(m, &huge_boot_pages, list) {
|
|
struct hstate *h = m->hstate;
|
|
struct page *page;
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
page = pfn_to_page(m->phys >> PAGE_SHIFT);
|
|
memblock_free_late(__pa(m),
|
|
sizeof(struct huge_bootmem_page));
|
|
#else
|
|
page = virt_to_page(m);
|
|
#endif
|
|
WARN_ON(page_count(page) != 1);
|
|
prep_compound_huge_page(page, h->order);
|
|
WARN_ON(PageReserved(page));
|
|
prep_new_huge_page(h, page, page_to_nid(page));
|
|
/*
|
|
* If we had gigantic hugepages allocated at boot time, we need
|
|
* to restore the 'stolen' pages to totalram_pages in order to
|
|
* fix confusing memory reports from free(1) and another
|
|
* side-effects, like CommitLimit going negative.
|
|
*/
|
|
if (hstate_is_gigantic(h))
|
|
adjust_managed_page_count(page, 1 << h->order);
|
|
}
|
|
}
|
|
|
|
static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
|
|
{
|
|
unsigned long i;
|
|
|
|
for (i = 0; i < h->max_huge_pages; ++i) {
|
|
if (hstate_is_gigantic(h)) {
|
|
if (!alloc_bootmem_huge_page(h))
|
|
break;
|
|
} else if (!alloc_fresh_huge_page(h,
|
|
&node_states[N_MEMORY]))
|
|
break;
|
|
}
|
|
h->max_huge_pages = i;
|
|
}
|
|
|
|
static void __init hugetlb_init_hstates(void)
|
|
{
|
|
struct hstate *h;
|
|
|
|
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);
|
|
}
|
|
VM_BUG_ON(minimum_order == UINT_MAX);
|
|
}
|
|
|
|
static char * __init memfmt(char *buf, unsigned long n)
|
|
{
|
|
if (n >= (1UL << 30))
|
|
sprintf(buf, "%lu GB", n >> 30);
|
|
else if (n >= (1UL << 20))
|
|
sprintf(buf, "%lu MB", n >> 20);
|
|
else
|
|
sprintf(buf, "%lu KB", n >> 10);
|
|
return buf;
|
|
}
|
|
|
|
static void __init report_hugepages(void)
|
|
{
|
|
struct hstate *h;
|
|
|
|
for_each_hstate(h) {
|
|
char buf[32];
|
|
pr_info("HugeTLB registered %s page size, pre-allocated %ld pages\n",
|
|
memfmt(buf, huge_page_size(h)),
|
|
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;
|
|
|
|
if (hstate_is_gigantic(h))
|
|
return;
|
|
|
|
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)
|
|
return;
|
|
if (PageHighMem(page))
|
|
continue;
|
|
list_del(&page->lru);
|
|
update_and_free_page(h, page);
|
|
h->free_huge_pages--;
|
|
h->free_huge_pages_node[page_to_nid(page)]--;
|
|
}
|
|
}
|
|
}
|
|
#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;
|
|
|
|
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 unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
|
|
nodemask_t *nodes_allowed)
|
|
{
|
|
unsigned long min_count, ret;
|
|
|
|
if (hstate_is_gigantic(h) && !gigantic_page_supported())
|
|
return h->max_huge_pages;
|
|
|
|
/*
|
|
* 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_buddy_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.
|
|
*/
|
|
spin_lock(&hugetlb_lock);
|
|
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(&hugetlb_lock);
|
|
if (hstate_is_gigantic(h))
|
|
ret = alloc_fresh_gigantic_page(h, nodes_allowed);
|
|
else
|
|
ret = alloc_fresh_huge_page(h, nodes_allowed);
|
|
spin_lock(&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_buddy_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);
|
|
while (min_count < persistent_huge_pages(h)) {
|
|
if (!free_pool_huge_page(h, nodes_allowed, 0))
|
|
break;
|
|
cond_resched_lock(&hugetlb_lock);
|
|
}
|
|
while (count < persistent_huge_pages(h)) {
|
|
if (!adjust_pool_surplus(h, nodes_allowed, 1))
|
|
break;
|
|
}
|
|
out:
|
|
ret = persistent_huge_pages(h);
|
|
spin_unlock(&hugetlb_lock);
|
|
return ret;
|
|
}
|
|
|
|
#define HSTATE_ATTR_RO(_name) \
|
|
static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
|
|
|
|
#define HSTATE_ATTR(_name) \
|
|
static struct kobj_attribute _name##_attr = \
|
|
__ATTR(_name, 0644, _name##_show, _name##_store)
|
|
|
|
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 sprintf(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_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY);
|
|
|
|
if (hstate_is_gigantic(h) && !gigantic_page_supported()) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
if (nid == NUMA_NO_NODE) {
|
|
/*
|
|
* global hstate attribute
|
|
*/
|
|
if (!(obey_mempolicy &&
|
|
init_nodemask_of_mempolicy(nodes_allowed))) {
|
|
NODEMASK_FREE(nodes_allowed);
|
|
nodes_allowed = &node_states[N_MEMORY];
|
|
}
|
|
} else if (nodes_allowed) {
|
|
/*
|
|
* per node hstate attribute: adjust count to global,
|
|
* but restrict alloc/free to the specified node.
|
|
*/
|
|
count += h->nr_huge_pages - h->nr_huge_pages_node[nid];
|
|
init_nodemask_of_node(nodes_allowed, nid);
|
|
} else
|
|
nodes_allowed = &node_states[N_MEMORY];
|
|
|
|
h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed);
|
|
|
|
if (nodes_allowed != &node_states[N_MEMORY])
|
|
NODEMASK_FREE(nodes_allowed);
|
|
|
|
return len;
|
|
out:
|
|
NODEMASK_FREE(nodes_allowed);
|
|
return err;
|
|
}
|
|
|
|
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 sprintf(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(&hugetlb_lock);
|
|
h->nr_overcommit_huge_pages = input;
|
|
spin_unlock(&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 sprintf(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 sprintf(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 sprintf(buf, "%lu\n", surplus_huge_pages);
|
|
}
|
|
HSTATE_ATTR_RO(surplus_hugepages);
|
|
|
|
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 struct attribute_group hstate_attr_group = {
|
|
.attrs = hstate_attrs,
|
|
};
|
|
|
|
static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
|
|
struct kobject **hstate_kobjs,
|
|
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]);
|
|
|
|
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 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;
|
|
|
|
if (!hugepages_supported())
|
|
return 0;
|
|
|
|
if (!size_to_hstate(default_hstate_size)) {
|
|
default_hstate_size = HPAGE_SIZE;
|
|
if (!size_to_hstate(default_hstate_size))
|
|
hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
|
|
}
|
|
default_hstate_idx = hstate_index(size_to_hstate(default_hstate_size));
|
|
if (default_hstate_max_huge_pages) {
|
|
if (!default_hstate.max_huge_pages)
|
|
default_hstate.max_huge_pages = default_hstate_max_huge_pages;
|
|
}
|
|
|
|
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(sizeof(struct mutex) * num_fault_mutexes, 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);
|
|
|
|
/* Should be called on processing a hugepagesz=... option */
|
|
void __init hugetlb_add_hstate(unsigned int order)
|
|
{
|
|
struct hstate *h;
|
|
unsigned long i;
|
|
|
|
if (size_to_hstate(PAGE_SIZE << order)) {
|
|
pr_warning("hugepagesz= specified twice, ignoring\n");
|
|
return;
|
|
}
|
|
BUG_ON(hugetlb_max_hstate >= HUGE_MAX_HSTATE);
|
|
BUG_ON(order == 0);
|
|
h = &hstates[hugetlb_max_hstate++];
|
|
h->order = order;
|
|
h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
|
|
h->nr_huge_pages = 0;
|
|
h->free_huge_pages = 0;
|
|
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_node(node_states[N_MEMORY]);
|
|
h->next_nid_to_free = first_node(node_states[N_MEMORY]);
|
|
snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
|
|
huge_page_size(h)/1024);
|
|
|
|
parsed_hstate = h;
|
|
}
|
|
|
|
static int __init hugetlb_nrpages_setup(char *s)
|
|
{
|
|
unsigned long *mhp;
|
|
static unsigned long *last_mhp;
|
|
|
|
/*
|
|
* !hugetlb_max_hstate means we haven't parsed a hugepagesz= parameter yet,
|
|
* so this hugepages= parameter goes to the "default hstate".
|
|
*/
|
|
if (!hugetlb_max_hstate)
|
|
mhp = &default_hstate_max_huge_pages;
|
|
else
|
|
mhp = &parsed_hstate->max_huge_pages;
|
|
|
|
if (mhp == last_mhp) {
|
|
pr_warning("hugepages= specified twice without "
|
|
"interleaving hugepagesz=, ignoring\n");
|
|
return 1;
|
|
}
|
|
|
|
if (sscanf(s, "%lu", mhp) <= 0)
|
|
*mhp = 0;
|
|
|
|
/*
|
|
* Global state is always initialized later in hugetlb_init.
|
|
* But we need to allocate >= MAX_ORDER hstates here early to still
|
|
* use the bootmem allocator.
|
|
*/
|
|
if (hugetlb_max_hstate && parsed_hstate->order >= MAX_ORDER)
|
|
hugetlb_hstate_alloc_pages(parsed_hstate);
|
|
|
|
last_mhp = mhp;
|
|
|
|
return 1;
|
|
}
|
|
__setup("hugepages=", hugetlb_nrpages_setup);
|
|
|
|
static int __init hugetlb_default_setup(char *s)
|
|
{
|
|
default_hstate_size = memparse(s, &s);
|
|
return 1;
|
|
}
|
|
__setup("default_hugepagesz=", hugetlb_default_setup);
|
|
|
|
static unsigned int cpuset_mems_nr(unsigned int *array)
|
|
{
|
|
int node;
|
|
unsigned int nr = 0;
|
|
|
|
for_each_node_mask(node, cpuset_current_mems_allowed)
|
|
nr += array[node];
|
|
|
|
return nr;
|
|
}
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
|
|
struct ctl_table *table, int write,
|
|
void __user *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 -ENOTSUPP;
|
|
|
|
table->data = &tmp;
|
|
table->maxlen = sizeof(unsigned long);
|
|
ret = proc_doulongvec_minmax(table, write, buffer, length, ppos);
|
|
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 __user *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 __user *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 __user *buffer,
|
|
size_t *length, loff_t *ppos)
|
|
{
|
|
struct hstate *h = &default_hstate;
|
|
unsigned long tmp;
|
|
int ret;
|
|
|
|
if (!hugepages_supported())
|
|
return -ENOTSUPP;
|
|
|
|
tmp = h->nr_overcommit_huge_pages;
|
|
|
|
if (write && hstate_is_gigantic(h))
|
|
return -EINVAL;
|
|
|
|
table->data = &tmp;
|
|
table->maxlen = sizeof(unsigned long);
|
|
ret = proc_doulongvec_minmax(table, write, buffer, length, ppos);
|
|
if (ret)
|
|
goto out;
|
|
|
|
if (write) {
|
|
spin_lock(&hugetlb_lock);
|
|
h->nr_overcommit_huge_pages = tmp;
|
|
spin_unlock(&hugetlb_lock);
|
|
}
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
#endif /* CONFIG_SYSCTL */
|
|
|
|
void hugetlb_report_meminfo(struct seq_file *m)
|
|
{
|
|
struct hstate *h = &default_hstate;
|
|
if (!hugepages_supported())
|
|
return;
|
|
seq_printf(m,
|
|
"HugePages_Total: %5lu\n"
|
|
"HugePages_Free: %5lu\n"
|
|
"HugePages_Rsvd: %5lu\n"
|
|
"HugePages_Surp: %5lu\n"
|
|
"Hugepagesize: %8lu kB\n",
|
|
h->nr_huge_pages,
|
|
h->free_huge_pages,
|
|
h->resv_huge_pages,
|
|
h->surplus_huge_pages,
|
|
1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
|
|
}
|
|
|
|
int hugetlb_report_node_meminfo(int nid, char *buf)
|
|
{
|
|
struct hstate *h = &default_hstate;
|
|
if (!hugepages_supported())
|
|
return 0;
|
|
return sprintf(buf,
|
|
"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],
|
|
1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
|
|
}
|
|
|
|
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;
|
|
|
|
spin_lock(&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.
|
|
*/
|
|
if (delta > 0) {
|
|
if (gather_surplus_pages(h, delta) < 0)
|
|
goto out;
|
|
|
|
if (delta > cpuset_mems_nr(h->free_huge_pages_node)) {
|
|
return_unused_surplus_pages(h, delta);
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
ret = 0;
|
|
if (delta < 0)
|
|
return_unused_surplus_pages(h, (unsigned long) -delta);
|
|
|
|
out:
|
|
spin_unlock(&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))
|
|
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);
|
|
|
|
kref_put(&resv->refs, resv_map_release);
|
|
|
|
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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We cannot handle pagefaults against hugetlb pages at all. They cause
|
|
* handle_mm_fault() to try to instantiate regular-sized pages in the
|
|
* hugegpage VMA. do_page_fault() is supposed to trap this, so BUG is we get
|
|
* this far.
|
|
*/
|
|
static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
|
|
{
|
|
BUG();
|
|
return 0;
|
|
}
|
|
|
|
const struct vm_operations_struct hugetlb_vm_ops = {
|
|
.fault = hugetlb_vm_op_fault,
|
|
.open = hugetlb_vm_op_open,
|
|
.close = hugetlb_vm_op_close,
|
|
};
|
|
|
|
static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
|
|
int writable)
|
|
{
|
|
pte_t entry;
|
|
|
|
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 = pte_mkhuge(entry);
|
|
entry = arch_make_huge_pte(entry, vma, page, writable);
|
|
|
|
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);
|
|
}
|
|
|
|
static int is_hugetlb_entry_migration(pte_t pte)
|
|
{
|
|
swp_entry_t swp;
|
|
|
|
if (huge_pte_none(pte) || pte_present(pte))
|
|
return 0;
|
|
swp = pte_to_swp_entry(pte);
|
|
if (non_swap_entry(swp) && is_migration_entry(swp))
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
static int is_hugetlb_entry_hwpoisoned(pte_t pte)
|
|
{
|
|
swp_entry_t swp;
|
|
|
|
if (huge_pte_none(pte) || pte_present(pte))
|
|
return 0;
|
|
swp = pte_to_swp_entry(pte);
|
|
if (non_swap_entry(swp) && is_hwpoison_entry(swp))
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
|
|
struct vm_area_struct *vma)
|
|
{
|
|
pte_t *src_pte, *dst_pte, entry;
|
|
struct page *ptepage;
|
|
unsigned long addr;
|
|
int cow;
|
|
struct hstate *h = hstate_vma(vma);
|
|
unsigned long sz = huge_page_size(h);
|
|
unsigned long mmun_start; /* For mmu_notifiers */
|
|
unsigned long mmun_end; /* For mmu_notifiers */
|
|
int ret = 0;
|
|
|
|
cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
|
|
|
|
mmun_start = vma->vm_start;
|
|
mmun_end = vma->vm_end;
|
|
if (cow)
|
|
mmu_notifier_invalidate_range_start(src, mmun_start, mmun_end);
|
|
|
|
for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
|
|
spinlock_t *src_ptl, *dst_ptl;
|
|
src_pte = huge_pte_offset(src, addr);
|
|
if (!src_pte)
|
|
continue;
|
|
dst_pte = huge_pte_alloc(dst, addr, sz);
|
|
if (!dst_pte) {
|
|
ret = -ENOMEM;
|
|
break;
|
|
}
|
|
|
|
/* If the pagetables are shared don't copy or take references */
|
|
if (dst_pte == src_pte)
|
|
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);
|
|
if (huge_pte_none(entry)) { /* skip none entry */
|
|
;
|
|
} else if (unlikely(is_hugetlb_entry_migration(entry) ||
|
|
is_hugetlb_entry_hwpoisoned(entry))) {
|
|
swp_entry_t swp_entry = pte_to_swp_entry(entry);
|
|
|
|
if (is_write_migration_entry(swp_entry) && cow) {
|
|
/*
|
|
* COW mappings require pages in both
|
|
* parent and child to be set to read.
|
|
*/
|
|
make_migration_entry_read(&swp_entry);
|
|
entry = swp_entry_to_pte(swp_entry);
|
|
set_huge_pte_at(src, addr, src_pte, entry);
|
|
}
|
|
set_huge_pte_at(dst, addr, dst_pte, entry);
|
|
} else {
|
|
if (cow) {
|
|
huge_ptep_set_wrprotect(src, addr, src_pte);
|
|
mmu_notifier_invalidate_range(src, mmun_start,
|
|
mmun_end);
|
|
}
|
|
entry = huge_ptep_get(src_pte);
|
|
ptepage = pte_page(entry);
|
|
get_page(ptepage);
|
|
page_dup_rmap(ptepage, true);
|
|
set_huge_pte_at(dst, addr, dst_pte, entry);
|
|
hugetlb_count_add(pages_per_huge_page(h), dst);
|
|
}
|
|
spin_unlock(src_ptl);
|
|
spin_unlock(dst_ptl);
|
|
}
|
|
|
|
if (cow)
|
|
mmu_notifier_invalidate_range_end(src, mmun_start, mmun_end);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
|
|
unsigned long start, unsigned long end,
|
|
struct page *ref_page)
|
|
{
|
|
int force_flush = 0;
|
|
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);
|
|
const unsigned long mmun_start = start; /* For mmu_notifiers */
|
|
const unsigned long mmun_end = end; /* For mmu_notifiers */
|
|
|
|
WARN_ON(!is_vm_hugetlb_page(vma));
|
|
BUG_ON(start & ~huge_page_mask(h));
|
|
BUG_ON(end & ~huge_page_mask(h));
|
|
|
|
tlb_start_vma(tlb, vma);
|
|
mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
|
|
address = start;
|
|
again:
|
|
for (; address < end; address += sz) {
|
|
ptep = huge_pte_offset(mm, address);
|
|
if (!ptep)
|
|
continue;
|
|
|
|
ptl = huge_pte_lock(h, mm, ptep);
|
|
if (huge_pmd_unshare(mm, &address, ptep))
|
|
goto unlock;
|
|
|
|
pte = huge_ptep_get(ptep);
|
|
if (huge_pte_none(pte))
|
|
goto unlock;
|
|
|
|
/*
|
|
* Migrating hugepage or HWPoisoned hugepage is already
|
|
* unmapped and its refcount is dropped, so just clear pte here.
|
|
*/
|
|
if (unlikely(!pte_present(pte))) {
|
|
huge_pte_clear(mm, address, ptep);
|
|
goto unlock;
|
|
}
|
|
|
|
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)
|
|
goto unlock;
|
|
|
|
/*
|
|
* 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_tlb_entry(tlb, ptep, address);
|
|
if (huge_pte_dirty(pte))
|
|
set_page_dirty(page);
|
|
|
|
hugetlb_count_sub(pages_per_huge_page(h), mm);
|
|
page_remove_rmap(page, true);
|
|
force_flush = !__tlb_remove_page(tlb, page);
|
|
if (force_flush) {
|
|
address += sz;
|
|
spin_unlock(ptl);
|
|
break;
|
|
}
|
|
/* Bail out after unmapping reference page if supplied */
|
|
if (ref_page) {
|
|
spin_unlock(ptl);
|
|
break;
|
|
}
|
|
unlock:
|
|
spin_unlock(ptl);
|
|
}
|
|
/*
|
|
* mmu_gather ran out of room to batch pages, we break out of
|
|
* the PTE lock to avoid doing the potential expensive TLB invalidate
|
|
* and page-free while holding it.
|
|
*/
|
|
if (force_flush) {
|
|
force_flush = 0;
|
|
tlb_flush_mmu(tlb);
|
|
if (address < end && !ref_page)
|
|
goto again;
|
|
}
|
|
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
|
|
tlb_end_vma(tlb, vma);
|
|
}
|
|
|
|
void __unmap_hugepage_range_final(struct mmu_gather *tlb,
|
|
struct vm_area_struct *vma, unsigned long start,
|
|
unsigned long end, struct page *ref_page)
|
|
{
|
|
__unmap_hugepage_range(tlb, vma, start, end, ref_page);
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
struct mm_struct *mm;
|
|
struct mmu_gather tlb;
|
|
|
|
mm = vma->vm_mm;
|
|
|
|
tlb_gather_mmu(&tlb, mm, start, end);
|
|
__unmap_hugepage_range(&tlb, vma, start, end, ref_page);
|
|
tlb_finish_mmu(&tlb, start, end);
|
|
}
|
|
|
|
/*
|
|
* This is called when the original mapper is failing to COW a MAP_PRIVATE
|
|
* mappping 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 = file_inode(vma->vm_file)->i_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);
|
|
}
|
|
i_mmap_unlock_write(mapping);
|
|
}
|
|
|
|
/*
|
|
* Hugetlb_cow() should be called with page lock of the original hugepage held.
|
|
* Called with hugetlb_instantiation_mutex 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 int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
|
|
unsigned long address, pte_t *ptep, pte_t pte,
|
|
struct page *pagecache_page, spinlock_t *ptl)
|
|
{
|
|
struct hstate *h = hstate_vma(vma);
|
|
struct page *old_page, *new_page;
|
|
int ret = 0, outside_reserve = 0;
|
|
unsigned long mmun_start; /* For mmu_notifiers */
|
|
unsigned long mmun_end; /* For mmu_notifiers */
|
|
|
|
old_page = pte_page(pte);
|
|
|
|
retry_avoidcopy:
|
|
/* If no-one else is actually using this page, avoid the copy
|
|
* and just make the page writable */
|
|
if (page_mapcount(old_page) == 1 && PageAnon(old_page)) {
|
|
page_move_anon_rmap(old_page, vma, address);
|
|
set_huge_ptep_writable(vma, address, ptep);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
page_cache_get(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, address, 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) {
|
|
page_cache_release(old_page);
|
|
BUG_ON(huge_pte_none(pte));
|
|
unmap_ref_private(mm, vma, old_page, address);
|
|
BUG_ON(huge_pte_none(pte));
|
|
spin_lock(ptl);
|
|
ptep = huge_pte_offset(mm, address & huge_page_mask(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.
|
|
*/
|
|
return 0;
|
|
}
|
|
|
|
ret = (PTR_ERR(new_page) == -ENOMEM) ?
|
|
VM_FAULT_OOM : VM_FAULT_SIGBUS;
|
|
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);
|
|
set_page_huge_active(new_page);
|
|
|
|
mmun_start = address & huge_page_mask(h);
|
|
mmun_end = mmun_start + huge_page_size(h);
|
|
mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
|
|
|
|
/*
|
|
* Retake the page table lock to check for racing updates
|
|
* before the page tables are altered
|
|
*/
|
|
spin_lock(ptl);
|
|
ptep = huge_pte_offset(mm, address & huge_page_mask(h));
|
|
if (likely(ptep && pte_same(huge_ptep_get(ptep), pte))) {
|
|
ClearPagePrivate(new_page);
|
|
|
|
/* Break COW */
|
|
huge_ptep_clear_flush(vma, address, ptep);
|
|
mmu_notifier_invalidate_range(mm, mmun_start, mmun_end);
|
|
set_huge_pte_at(mm, address, ptep,
|
|
make_huge_pte(vma, new_page, 1));
|
|
page_remove_rmap(old_page, true);
|
|
hugepage_add_new_anon_rmap(new_page, vma, address);
|
|
/* Make the old page be freed below */
|
|
new_page = old_page;
|
|
}
|
|
spin_unlock(ptl);
|
|
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
|
|
out_release_all:
|
|
page_cache_release(new_page);
|
|
out_release_old:
|
|
page_cache_release(old_page);
|
|
|
|
spin_lock(ptl); /* Caller expects lock to be held */
|
|
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;
|
|
ClearPagePrivate(page);
|
|
|
|
spin_lock(&inode->i_lock);
|
|
inode->i_blocks += blocks_per_huge_page(h);
|
|
spin_unlock(&inode->i_lock);
|
|
return 0;
|
|
}
|
|
|
|
static int 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, unsigned int flags)
|
|
{
|
|
struct hstate *h = hstate_vma(vma);
|
|
int ret = VM_FAULT_SIGBUS;
|
|
int anon_rmap = 0;
|
|
unsigned long size;
|
|
struct page *page;
|
|
pte_t new_pte;
|
|
spinlock_t *ptl;
|
|
|
|
/*
|
|
* 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. Warn that such a situation has occurred as it may not be obvious
|
|
*/
|
|
if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) {
|
|
pr_warning("PID %d killed due to inadequate hugepage pool\n",
|
|
current->pid);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Use page lock to guard against racing truncation
|
|
* before we get page_table_lock.
|
|
*/
|
|
retry:
|
|
page = find_lock_page(mapping, idx);
|
|
if (!page) {
|
|
size = i_size_read(mapping->host) >> huge_page_shift(h);
|
|
if (idx >= size)
|
|
goto out;
|
|
page = alloc_huge_page(vma, address, 0);
|
|
if (IS_ERR(page)) {
|
|
ret = PTR_ERR(page);
|
|
if (ret == -ENOMEM)
|
|
ret = VM_FAULT_OOM;
|
|
else
|
|
ret = VM_FAULT_SIGBUS;
|
|
goto out;
|
|
}
|
|
clear_huge_page(page, address, pages_per_huge_page(h));
|
|
__SetPageUptodate(page);
|
|
set_page_huge_active(page);
|
|
|
|
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;
|
|
}
|
|
} 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 |
|
|
VM_FAULT_SET_HINDEX(hstate_index(h));
|
|
goto backout_unlocked;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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, address) < 0) {
|
|
ret = VM_FAULT_OOM;
|
|
goto backout_unlocked;
|
|
}
|
|
/* Just decrements count, does not deallocate */
|
|
vma_end_reservation(h, vma, address);
|
|
}
|
|
|
|
ptl = huge_pte_lockptr(h, mm, ptep);
|
|
spin_lock(ptl);
|
|
size = i_size_read(mapping->host) >> huge_page_shift(h);
|
|
if (idx >= size)
|
|
goto backout;
|
|
|
|
ret = 0;
|
|
if (!huge_pte_none(huge_ptep_get(ptep)))
|
|
goto backout;
|
|
|
|
if (anon_rmap) {
|
|
ClearPagePrivate(page);
|
|
hugepage_add_new_anon_rmap(page, vma, address);
|
|
} else
|
|
page_dup_rmap(page, true);
|
|
new_pte = make_huge_pte(vma, page, ((vma->vm_flags & VM_WRITE)
|
|
&& (vma->vm_flags & VM_SHARED)));
|
|
set_huge_pte_at(mm, address, 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_cow(mm, vma, address, ptep, new_pte, page, ptl);
|
|
}
|
|
|
|
spin_unlock(ptl);
|
|
unlock_page(page);
|
|
out:
|
|
return ret;
|
|
|
|
backout:
|
|
spin_unlock(ptl);
|
|
backout_unlocked:
|
|
unlock_page(page);
|
|
put_page(page);
|
|
goto out;
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
|
|
struct vm_area_struct *vma,
|
|
struct address_space *mapping,
|
|
pgoff_t idx, unsigned long address)
|
|
{
|
|
unsigned long key[2];
|
|
u32 hash;
|
|
|
|
if (vma->vm_flags & VM_SHARED) {
|
|
key[0] = (unsigned long) mapping;
|
|
key[1] = idx;
|
|
} else {
|
|
key[0] = (unsigned long) mm;
|
|
key[1] = address >> huge_page_shift(h);
|
|
}
|
|
|
|
hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0);
|
|
|
|
return hash & (num_fault_mutexes - 1);
|
|
}
|
|
#else
|
|
/*
|
|
* For uniprocesor systems we always use a single mutex, so just
|
|
* return 0 and avoid the hashing overhead.
|
|
*/
|
|
u32 hugetlb_fault_mutex_hash(struct hstate *h, struct mm_struct *mm,
|
|
struct vm_area_struct *vma,
|
|
struct address_space *mapping,
|
|
pgoff_t idx, unsigned long address)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
|
|
unsigned long address, unsigned int flags)
|
|
{
|
|
pte_t *ptep, entry;
|
|
spinlock_t *ptl;
|
|
int 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;
|
|
|
|
address &= huge_page_mask(h);
|
|
|
|
ptep = huge_pte_offset(mm, address);
|
|
if (ptep) {
|
|
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));
|
|
} else {
|
|
ptep = huge_pte_alloc(mm, address, huge_page_size(h));
|
|
if (!ptep)
|
|
return VM_FAULT_OOM;
|
|
}
|
|
|
|
mapping = vma->vm_file->f_mapping;
|
|
idx = vma_hugecache_offset(h, vma, address);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping, idx, address);
|
|
mutex_lock(&hugetlb_fault_mutex_table[hash]);
|
|
|
|
entry = huge_ptep_get(ptep);
|
|
if (huge_pte_none(entry)) {
|
|
ret = hugetlb_no_page(mm, vma, mapping, idx, address, ptep, 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
|
|
* a 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 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) && !huge_pte_write(entry)) {
|
|
if (vma_needs_reservation(h, vma, address) < 0) {
|
|
ret = VM_FAULT_OOM;
|
|
goto out_mutex;
|
|
}
|
|
/* Just decrements count, does not deallocate */
|
|
vma_end_reservation(h, vma, address);
|
|
|
|
if (!(vma->vm_flags & VM_MAYSHARE))
|
|
pagecache_page = hugetlbfs_pagecache_page(h,
|
|
vma, address);
|
|
}
|
|
|
|
ptl = huge_pte_lock(h, mm, ptep);
|
|
|
|
/* Check for a racing update before calling hugetlb_cow */
|
|
if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
|
|
goto out_ptl;
|
|
|
|
/*
|
|
* hugetlb_cow() 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) {
|
|
if (!huge_pte_write(entry)) {
|
|
ret = hugetlb_cow(mm, vma, address, ptep, entry,
|
|
pagecache_page, ptl);
|
|
goto out_put_page;
|
|
}
|
|
entry = huge_pte_mkdirty(entry);
|
|
}
|
|
entry = pte_mkyoung(entry);
|
|
if (huge_ptep_set_access_flags(vma, address, ptep, entry,
|
|
flags & FAULT_FLAG_WRITE))
|
|
update_mmu_cache(vma, address, 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]);
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
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)
|
|
{
|
|
unsigned long pfn_offset;
|
|
unsigned long vaddr = *position;
|
|
unsigned long remainder = *nr_pages;
|
|
struct hstate *h = hstate_vma(vma);
|
|
|
|
while (vaddr < vma->vm_end && remainder) {
|
|
pte_t *pte;
|
|
spinlock_t *ptl = NULL;
|
|
int absent;
|
|
struct page *page;
|
|
|
|
/*
|
|
* If we have a pending SIGKILL, don't keep faulting pages and
|
|
* potentially allocating memory.
|
|
*/
|
|
if (unlikely(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));
|
|
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 || is_swap_pte(huge_ptep_get(pte)) ||
|
|
((flags & FOLL_WRITE) &&
|
|
!huge_pte_write(huge_ptep_get(pte)))) {
|
|
int ret;
|
|
|
|
if (pte)
|
|
spin_unlock(ptl);
|
|
ret = hugetlb_fault(mm, vma, vaddr,
|
|
(flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0);
|
|
if (!(ret & VM_FAULT_ERROR))
|
|
continue;
|
|
|
|
remainder = 0;
|
|
break;
|
|
}
|
|
|
|
pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
|
|
page = pte_page(huge_ptep_get(pte));
|
|
same_page:
|
|
if (pages) {
|
|
pages[i] = mem_map_offset(page, pfn_offset);
|
|
get_page(pages[i]);
|
|
}
|
|
|
|
if (vmas)
|
|
vmas[i] = vma;
|
|
|
|
vaddr += PAGE_SIZE;
|
|
++pfn_offset;
|
|
--remainder;
|
|
++i;
|
|
if (vaddr < vma->vm_end && remainder &&
|
|
pfn_offset < pages_per_huge_page(h)) {
|
|
/*
|
|
* We use pfn_offset to avoid touching the pageframes
|
|
* of this compound page.
|
|
*/
|
|
goto same_page;
|
|
}
|
|
spin_unlock(ptl);
|
|
}
|
|
*nr_pages = remainder;
|
|
*position = vaddr;
|
|
|
|
return i ? i : -EFAULT;
|
|
}
|
|
|
|
unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
|
|
unsigned long address, unsigned long end, pgprot_t newprot)
|
|
{
|
|
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;
|
|
|
|
BUG_ON(address >= end);
|
|
flush_cache_range(vma, address, end);
|
|
|
|
mmu_notifier_invalidate_range_start(mm, start, end);
|
|
i_mmap_lock_write(vma->vm_file->f_mapping);
|
|
for (; address < end; address += huge_page_size(h)) {
|
|
spinlock_t *ptl;
|
|
ptep = huge_pte_offset(mm, address);
|
|
if (!ptep)
|
|
continue;
|
|
ptl = huge_pte_lock(h, mm, ptep);
|
|
if (huge_pmd_unshare(mm, &address, ptep)) {
|
|
pages++;
|
|
spin_unlock(ptl);
|
|
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);
|
|
|
|
if (is_write_migration_entry(entry)) {
|
|
pte_t newpte;
|
|
|
|
make_migration_entry_read(&entry);
|
|
newpte = swp_entry_to_pte(entry);
|
|
set_huge_pte_at(mm, address, ptep, newpte);
|
|
pages++;
|
|
}
|
|
spin_unlock(ptl);
|
|
continue;
|
|
}
|
|
if (!huge_pte_none(pte)) {
|
|
pte = huge_ptep_get_and_clear(mm, address, ptep);
|
|
pte = pte_mkhuge(huge_pte_modify(pte, newprot));
|
|
pte = arch_make_huge_pte(pte, vma, NULL, 0);
|
|
set_huge_pte_at(mm, address, ptep, pte);
|
|
pages++;
|
|
}
|
|
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.
|
|
*/
|
|
flush_tlb_range(vma, start, end);
|
|
mmu_notifier_invalidate_range(mm, start, end);
|
|
i_mmap_unlock_write(vma->vm_file->f_mapping);
|
|
mmu_notifier_invalidate_range_end(mm, start, end);
|
|
|
|
return pages << h->order;
|
|
}
|
|
|
|
int hugetlb_reserve_pages(struct inode *inode,
|
|
long from, long to,
|
|
struct vm_area_struct *vma,
|
|
vm_flags_t vm_flags)
|
|
{
|
|
long ret, chg;
|
|
struct hstate *h = hstate_inode(inode);
|
|
struct hugepage_subpool *spool = subpool_inode(inode);
|
|
struct resv_map *resv_map;
|
|
long gbl_reserve;
|
|
|
|
/*
|
|
* 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 0;
|
|
|
|
/*
|
|
* 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 = inode_resv_map(inode);
|
|
|
|
chg = region_chg(resv_map, from, to);
|
|
|
|
} else {
|
|
resv_map = resv_map_alloc();
|
|
if (!resv_map)
|
|
return -ENOMEM;
|
|
|
|
chg = to - from;
|
|
|
|
set_vma_resv_map(vma, resv_map);
|
|
set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
|
|
}
|
|
|
|
if (chg < 0) {
|
|
ret = chg;
|
|
goto out_err;
|
|
}
|
|
|
|
/*
|
|
* 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) {
|
|
ret = -ENOSPC;
|
|
goto out_err;
|
|
}
|
|
|
|
/*
|
|
* Check enough hugepages are available for the reservation.
|
|
* Hand the pages back to the subpool if there are not
|
|
*/
|
|
ret = hugetlb_acct_memory(h, gbl_reserve);
|
|
if (ret < 0) {
|
|
/* put back original number of pages, chg */
|
|
(void)hugepage_subpool_put_pages(spool, chg);
|
|
goto out_err;
|
|
}
|
|
|
|
/*
|
|
* 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) {
|
|
long add = region_add(resv_map, from, to);
|
|
|
|
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;
|
|
|
|
rsv_adjust = hugepage_subpool_put_pages(spool,
|
|
chg - add);
|
|
hugetlb_acct_memory(h, -rsv_adjust);
|
|
}
|
|
}
|
|
return 0;
|
|
out_err:
|
|
if (!vma || vma->vm_flags & VM_MAYSHARE)
|
|
region_abort(resv_map, from, to);
|
|
if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER))
|
|
kref_put(&resv_map->refs, resv_map_release);
|
|
return ret;
|
|
}
|
|
|
|
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;
|
|
|
|
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.
|
|
*/
|
|
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 ||
|
|
sbase < svma->vm_start || svma->vm_end < 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 &&
|
|
vma->vm_start <= base && end <= vma->vm_end)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* 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. pmd allocation is essential for the shared case because
|
|
* pud has to be populated inside the same i_mmap_rwsem section - otherwise
|
|
* racing tasks could either miss the sharing (see huge_pte_offset) or select a
|
|
* bad pmd for sharing.
|
|
*/
|
|
pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
|
|
{
|
|
struct vm_area_struct *vma = find_vma(mm, addr);
|
|
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;
|
|
|
|
if (!vma_shareable(vma, addr))
|
|
return (pte_t *)pmd_alloc(mm, pud, addr);
|
|
|
|
i_mmap_lock_write(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);
|
|
if (spte) {
|
|
mm_inc_nr_pmds(mm);
|
|
get_page(virt_to_page(spte));
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!spte)
|
|
goto out;
|
|
|
|
ptl = huge_pte_lockptr(hstate_vma(vma), mm, spte);
|
|
spin_lock(ptl);
|
|
if (pud_none(*pud)) {
|
|
pud_populate(mm, pud,
|
|
(pmd_t *)((unsigned long)spte & PAGE_MASK));
|
|
} else {
|
|
put_page(virt_to_page(spte));
|
|
mm_inc_nr_pmds(mm);
|
|
}
|
|
spin_unlock(ptl);
|
|
out:
|
|
pte = (pte_t *)pmd_alloc(mm, pud, addr);
|
|
i_mmap_unlock_write(mapping);
|
|
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.
|
|
*
|
|
* 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, unsigned long *addr, pte_t *ptep)
|
|
{
|
|
pgd_t *pgd = pgd_offset(mm, *addr);
|
|
pud_t *pud = pud_offset(pgd, *addr);
|
|
|
|
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);
|
|
*addr = ALIGN(*addr, HPAGE_SIZE * PTRS_PER_PTE) - HPAGE_SIZE;
|
|
return 1;
|
|
}
|
|
#define want_pmd_share() (1)
|
|
#else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
|
|
pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
|
|
{
|
|
return 0;
|
|
}
|
|
#define want_pmd_share() (0)
|
|
#endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
|
|
|
|
#ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
|
|
pte_t *huge_pte_alloc(struct mm_struct *mm,
|
|
unsigned long addr, unsigned long sz)
|
|
{
|
|
pgd_t *pgd;
|
|
pud_t *pud;
|
|
pte_t *pte = NULL;
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
pud = pud_alloc(mm, pgd, addr);
|
|
if (pud) {
|
|
if (sz == PUD_SIZE) {
|
|
pte = (pte_t *)pud;
|
|
} else {
|
|
BUG_ON(sz != PMD_SIZE);
|
|
if (want_pmd_share() && pud_none(*pud))
|
|
pte = huge_pmd_share(mm, addr, pud);
|
|
else
|
|
pte = (pte_t *)pmd_alloc(mm, pud, addr);
|
|
}
|
|
}
|
|
BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte));
|
|
|
|
return pte;
|
|
}
|
|
|
|
pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
|
|
{
|
|
pgd_t *pgd;
|
|
pud_t *pud;
|
|
pmd_t *pmd = NULL;
|
|
|
|
pgd = pgd_offset(mm, addr);
|
|
if (pgd_present(*pgd)) {
|
|
pud = pud_offset(pgd, addr);
|
|
if (pud_present(*pud)) {
|
|
if (pud_huge(*pud))
|
|
return (pte_t *)pud;
|
|
pmd = pmd_offset(pud, addr);
|
|
}
|
|
}
|
|
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_pmd(struct mm_struct *mm, unsigned long address,
|
|
pmd_t *pmd, int flags)
|
|
{
|
|
struct page *page = NULL;
|
|
spinlock_t *ptl;
|
|
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;
|
|
if (pmd_present(*pmd)) {
|
|
page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT);
|
|
if (flags & FOLL_GET)
|
|
get_page(page);
|
|
} else {
|
|
if (is_hugetlb_entry_migration(huge_ptep_get((pte_t *)pmd))) {
|
|
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)
|
|
return NULL;
|
|
|
|
return pte_page(*(pte_t *)pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
|
|
}
|
|
|
|
#ifdef CONFIG_MEMORY_FAILURE
|
|
|
|
/*
|
|
* This function is called from memory failure code.
|
|
* Assume the caller holds page lock of the head page.
|
|
*/
|
|
int dequeue_hwpoisoned_huge_page(struct page *hpage)
|
|
{
|
|
struct hstate *h = page_hstate(hpage);
|
|
int nid = page_to_nid(hpage);
|
|
int ret = -EBUSY;
|
|
|
|
spin_lock(&hugetlb_lock);
|
|
/*
|
|
* Just checking !page_huge_active is not enough, because that could be
|
|
* an isolated/hwpoisoned hugepage (which have >0 refcount).
|
|
*/
|
|
if (!page_huge_active(hpage) && !page_count(hpage)) {
|
|
/*
|
|
* Hwpoisoned hugepage isn't linked to activelist or freelist,
|
|
* but dangling hpage->lru can trigger list-debug warnings
|
|
* (this happens when we call unpoison_memory() on it),
|
|
* so let it point to itself with list_del_init().
|
|
*/
|
|
list_del_init(&hpage->lru);
|
|
set_page_refcounted(hpage);
|
|
h->free_huge_pages--;
|
|
h->free_huge_pages_node[nid]--;
|
|
ret = 0;
|
|
}
|
|
spin_unlock(&hugetlb_lock);
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
bool isolate_huge_page(struct page *page, struct list_head *list)
|
|
{
|
|
bool ret = true;
|
|
|
|
VM_BUG_ON_PAGE(!PageHead(page), page);
|
|
spin_lock(&hugetlb_lock);
|
|
if (!page_huge_active(page) || !get_page_unless_zero(page)) {
|
|
ret = false;
|
|
goto unlock;
|
|
}
|
|
clear_page_huge_active(page);
|
|
list_move_tail(&page->lru, list);
|
|
unlock:
|
|
spin_unlock(&hugetlb_lock);
|
|
return ret;
|
|
}
|
|
|
|
void putback_active_hugepage(struct page *page)
|
|
{
|
|
VM_BUG_ON_PAGE(!PageHead(page), page);
|
|
spin_lock(&hugetlb_lock);
|
|
set_page_huge_active(page);
|
|
list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist);
|
|
spin_unlock(&hugetlb_lock);
|
|
put_page(page);
|
|
}
|