alistair23-linux/fs/xfs/kmem.c
Eric Sandeen 847f9f6875 xfs: more info from kmem deadlocks and high-level error msgs
In an effort to get more useful out of "possible memory
allocation deadlock" messages, print the size of the
requested allocation, and dump the stack if the xfs error
level is tuned high.

The stack dump is implemented in define_xfs_printk_level()
for error levels >= LOGLEVEL_ERR, partly because it
seems generically useful, and also because kmem.c has
no knowledge of xfs error level tunables or other such bits,
it's very kmem-specific.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-10-12 16:04:45 +11:00

130 lines
3.2 KiB
C

/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include "kmem.h"
#include "xfs_message.h"
/*
* Greedy allocation. May fail and may return vmalloced memory.
*/
void *
kmem_zalloc_greedy(size_t *size, size_t minsize, size_t maxsize)
{
void *ptr;
size_t kmsize = maxsize;
while (!(ptr = vzalloc(kmsize))) {
if ((kmsize >>= 1) <= minsize)
kmsize = minsize;
}
if (ptr)
*size = kmsize;
return ptr;
}
void *
kmem_alloc(size_t size, xfs_km_flags_t flags)
{
int retries = 0;
gfp_t lflags = kmem_flags_convert(flags);
void *ptr;
do {
ptr = kmalloc(size, lflags);
if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
return ptr;
if (!(++retries % 100))
xfs_err(NULL,
"%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
current->comm, current->pid,
(unsigned int)size, __func__, lflags);
congestion_wait(BLK_RW_ASYNC, HZ/50);
} while (1);
}
void *
kmem_zalloc_large(size_t size, xfs_km_flags_t flags)
{
unsigned noio_flag = 0;
void *ptr;
gfp_t lflags;
ptr = kmem_zalloc(size, flags | KM_MAYFAIL);
if (ptr)
return ptr;
/*
* __vmalloc() will allocate data pages and auxillary structures (e.g.
* pagetables) with GFP_KERNEL, yet we may be under GFP_NOFS context
* here. Hence we need to tell memory reclaim that we are in such a
* context via PF_MEMALLOC_NOIO to prevent memory reclaim re-entering
* the filesystem here and potentially deadlocking.
*/
if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
noio_flag = memalloc_noio_save();
lflags = kmem_flags_convert(flags);
ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL);
if ((current->flags & PF_FSTRANS) || (flags & KM_NOFS))
memalloc_noio_restore(noio_flag);
return ptr;
}
void *
kmem_realloc(const void *ptr, size_t newsize, size_t oldsize,
xfs_km_flags_t flags)
{
void *new;
new = kmem_alloc(newsize, flags);
if (ptr) {
if (new)
memcpy(new, ptr,
((oldsize < newsize) ? oldsize : newsize));
kmem_free(ptr);
}
return new;
}
void *
kmem_zone_alloc(kmem_zone_t *zone, xfs_km_flags_t flags)
{
int retries = 0;
gfp_t lflags = kmem_flags_convert(flags);
void *ptr;
do {
ptr = kmem_cache_alloc(zone, lflags);
if (ptr || (flags & (KM_MAYFAIL|KM_NOSLEEP)))
return ptr;
if (!(++retries % 100))
xfs_err(NULL,
"%s(%u) possible memory allocation deadlock in %s (mode:0x%x)",
current->comm, current->pid,
__func__, lflags);
congestion_wait(BLK_RW_ASYNC, HZ/50);
} while (1);
}