cb0a8d2302
When using large directory blocks, we regularly see memory allocations of >64k being made for the shadow log vector buffer. When we are under memory pressure, kmalloc() may not be able to find contiguous memory chunks large enough to satisfy these allocations easily, and if memory is fragmented we can potentially stall here. TO avoid this problem, switch the log vector buffer allocation to use kmem_alloc_large(). This will allow failed allocations to fall back to vmalloc and so remove the dependency on large contiguous regions of memory being available. This should prevent slowdowns and potential stalls when memory is low and/or fragmented. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
117 lines
3.1 KiB
C
117 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_alloc_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_alloc(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, 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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