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![Michal Hocko](/assets/img/avatar_default.png)
__vmalloc* allows users to provide gfp flags for the underlying allocation. This API is quite popular $ git grep "=[[:space:]]__vmalloc\|return[[:space:]]*__vmalloc" | wc -l 77 The only problem is that many people are not aware that they really want to give __GFP_HIGHMEM along with other flags because there is really no reason to consume precious lowmemory on CONFIG_HIGHMEM systems for pages which are mapped to the kernel vmalloc space. About half of users don't use this flag, though. This signals that we make the API unnecessarily too complex. This patch simply uses __GFP_HIGHMEM implicitly when allocating pages to be mapped to the vmalloc space. Current users which add __GFP_HIGHMEM are simplified and drop the flag. Link: http://lkml.kernel.org/r/20170307141020.29107-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Cristopher Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
116 lines
3.1 KiB
C
116 lines
3.1 KiB
C
/*
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* Copyright (c) 2000-2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it would be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/mm.h>
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#include <linux/sched/mm.h>
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#include <linux/highmem.h>
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#include <linux/slab.h>
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#include <linux/swap.h>
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#include <linux/blkdev.h>
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#include <linux/backing-dev.h>
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#include "kmem.h"
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#include "xfs_message.h"
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void *
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kmem_alloc(size_t size, xfs_km_flags_t flags)
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{
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int retries = 0;
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gfp_t lflags = kmem_flags_convert(flags);
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void *ptr;
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do {
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ptr = kmalloc(size, lflags);
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if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
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return ptr;
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if (!(++retries % 100))
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xfs_err(NULL,
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"%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
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current->comm, current->pid,
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(unsigned int)size, __func__, lflags);
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congestion_wait(BLK_RW_ASYNC, HZ/50);
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} while (1);
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}
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void *
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kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
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{
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unsigned nofs_flag = 0;
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void *ptr;
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gfp_t lflags;
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ptr = kmem_zalloc(size, flags | KM_MAYFAIL);
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if (ptr)
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return ptr;
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/*
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* __vmalloc() will allocate data pages and auxillary structures (e.g.
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* pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
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* here. Hence we need to tell memory reclaim that we are in such a
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* context via PF_MEMALLOC_NOFS to prevent memory reclaim re-entering
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* the filesystem here and potentially deadlocking.
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*/
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if (flags & KM_NOFS)
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nofs_flag = memalloc_nofs_save();
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lflags = kmem_flags_convert(flags);
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ptr = __vmalloc(size, lflags | __GFP_ZERO, PAGE_KERNEL);
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if (flags & KM_NOFS)
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memalloc_nofs_restore(nofs_flag);
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return ptr;
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}
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void *
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kmem_realloc(const void *old, size_t newsize, xfs_km_flags_t flags)
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{
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int retries = 0;
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gfp_t lflags = kmem_flags_convert(flags);
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void *ptr;
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do {
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ptr = krealloc(old, newsize, lflags);
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if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
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return ptr;
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if (!(++retries % 100))
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xfs_err(NULL,
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"%s(%u) possible memory allocation deadlock size %zu in %s (mode:0x%x)",
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current->comm, current->pid,
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newsize, __func__, lflags);
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congestion_wait(BLK_RW_ASYNC, HZ/50);
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} while (1);
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}
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void *
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kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
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{
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int retries = 0;
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gfp_t lflags = kmem_flags_convert(flags);
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void *ptr;
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do {
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ptr = kmem_cache_alloc(zone, lflags);
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if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
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return ptr;
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if (!(++retries % 100))
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xfs_err(NULL,
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"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
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current->comm, current->pid,
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__func__, lflags);
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congestion_wait(BLK_RW_ASYNC, HZ/50);
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} while (1);
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}
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