Revision df9576def004d2cd5beedc00cb6e8901427634b9 authored by Yang Shi on 03 August 2019, 04:48:37 UTC, committed by Linus Torvalds on 03 August 2019, 14:02:00 UTC
When running ltp's oom test with kmemleak enabled, the below warning was
triggerred since kernel detects __GFP_NOFAIL & ~__GFP_DIRECT_RECLAIM is
passed in:

  WARNING: CPU: 105 PID: 2138 at mm/page_alloc.c:4608 __alloc_pages_nodemask+0x1c31/0x1d50
  Modules linked in: loop dax_pmem dax_pmem_core ip_tables x_tables xfs virtio_net net_failover virtio_blk failover ata_generic virtio_pci virtio_ring virtio libata
  CPU: 105 PID: 2138 Comm: oom01 Not tainted 5.2.0-next-20190710+ #7
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
  RIP: 0010:__alloc_pages_nodemask+0x1c31/0x1d50
  ...
   kmemleak_alloc+0x4e/0xb0
   kmem_cache_alloc+0x2a7/0x3e0
   mempool_alloc_slab+0x2d/0x40
   mempool_alloc+0x118/0x2b0
   bio_alloc_bioset+0x19d/0x350
   get_swap_bio+0x80/0x230
   __swap_writepage+0x5ff/0xb20

The mempool_alloc_slab() clears __GFP_DIRECT_RECLAIM, however kmemleak
has __GFP_NOFAIL set all the time due to d9570ee3bd1d4f2 ("kmemleak:
allow to coexist with fault injection").  But, it doesn't make any sense
to have __GFP_NOFAIL and ~__GFP_DIRECT_RECLAIM specified at the same
time.

According to the discussion on the mailing list, the commit should be
reverted for short term solution.  Catalin Marinas would follow up with
a better solution for longer term.

The failure rate of kmemleak metadata allocation may increase in some
circumstances, but this should be expected side effect.

Link: http://lkml.kernel.org/r/1563299431-111710-1-git-send-email-yang.shi@linux.alibaba.com
Fixes: d9570ee3bd1d4f2 ("kmemleak: allow to coexist with fault injection")
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 68d8681
Raw File
debug.h
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * debug.h - NTFS kernel debug support. Part of the Linux-NTFS project.
 *
 * Copyright (c) 2001-2004 Anton Altaparmakov
 */

#ifndef _LINUX_NTFS_DEBUG_H
#define _LINUX_NTFS_DEBUG_H

#include <linux/fs.h>

#include "runlist.h"

#ifdef DEBUG

extern int debug_msgs;

extern __printf(4, 5)
void __ntfs_debug(const char *file, int line, const char *function,
		  const char *format, ...);
/**
 * ntfs_debug - write a debug level message to syslog
 * @f:		a printf format string containing the message
 * @...:	the variables to substitute into @f
 *
 * ntfs_debug() writes a DEBUG level message to the syslog but only if the
 * driver was compiled with -DDEBUG. Otherwise, the call turns into a NOP.
 */
#define ntfs_debug(f, a...)						\
	__ntfs_debug(__FILE__, __LINE__, __func__, f, ##a)

extern void ntfs_debug_dump_runlist(const runlist_element *rl);

#else	/* !DEBUG */

#define ntfs_debug(fmt, ...)						\
do {									\
	if (0)								\
		no_printk(fmt, ##__VA_ARGS__);				\
} while (0)

#define ntfs_debug_dump_runlist(rl)	do {} while (0)

#endif	/* !DEBUG */

extern  __printf(3, 4)
void __ntfs_warning(const char *function, const struct super_block *sb,
		    const char *fmt, ...);
#define ntfs_warning(sb, f, a...)	__ntfs_warning(__func__, sb, f, ##a)

extern  __printf(3, 4)
void __ntfs_error(const char *function, const struct super_block *sb,
		  const char *fmt, ...);
#define ntfs_error(sb, f, a...)		__ntfs_error(__func__, sb, f, ##a)

#endif /* _LINUX_NTFS_DEBUG_H */
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