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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 
Revert "kmemleak: allow to coexist with fault injection"
 
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
blk-mq-debugfs.h 
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef INT_BLK_MQ_DEBUGFS_H
#define INT_BLK_MQ_DEBUGFS_H

#ifdef CONFIG_BLK_DEBUG_FS

#include <linux/seq_file.h>

struct blk_mq_debugfs_attr {
	const char *name;
	umode_t mode;
	int (*show)(void *, struct seq_file *);
	ssize_t (*write)(void *, const char __user *, size_t, loff_t *);
	/* Set either .show or .seq_ops. */
	const struct seq_operations *seq_ops;
};

int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq);
int blk_mq_debugfs_rq_show(struct seq_file *m, void *v);

void blk_mq_debugfs_register(struct request_queue *q);
void blk_mq_debugfs_unregister(struct request_queue *q);
void blk_mq_debugfs_register_hctx(struct request_queue *q,
				  struct blk_mq_hw_ctx *hctx);
void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx);
void blk_mq_debugfs_register_hctxs(struct request_queue *q);
void blk_mq_debugfs_unregister_hctxs(struct request_queue *q);

void blk_mq_debugfs_register_sched(struct request_queue *q);
void blk_mq_debugfs_unregister_sched(struct request_queue *q);
void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
				       struct blk_mq_hw_ctx *hctx);
void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx);

void blk_mq_debugfs_register_rqos(struct rq_qos *rqos);
void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos);
void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q);
#else
static inline void blk_mq_debugfs_register(struct request_queue *q)
{
}

static inline void blk_mq_debugfs_unregister(struct request_queue *q)
{
}

static inline void blk_mq_debugfs_register_hctx(struct request_queue *q,
						struct blk_mq_hw_ctx *hctx)
{
}

static inline void blk_mq_debugfs_unregister_hctx(struct blk_mq_hw_ctx *hctx)
{
}

static inline void blk_mq_debugfs_register_hctxs(struct request_queue *q)
{
}

static inline void blk_mq_debugfs_unregister_hctxs(struct request_queue *q)
{
}

static inline void blk_mq_debugfs_register_sched(struct request_queue *q)
{
}

static inline void blk_mq_debugfs_unregister_sched(struct request_queue *q)
{
}

static inline void blk_mq_debugfs_register_sched_hctx(struct request_queue *q,
						      struct blk_mq_hw_ctx *hctx)
{
}

static inline void blk_mq_debugfs_unregister_sched_hctx(struct blk_mq_hw_ctx *hctx)
{
}

static inline void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
{
}

static inline void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
{
}

static inline void blk_mq_debugfs_unregister_queue_rqos(struct request_queue *q)
{
}
#endif

#ifdef CONFIG_BLK_DEBUG_FS_ZONED
int queue_zone_wlock_show(void *data, struct seq_file *m);
#else
static inline int queue_zone_wlock_show(void *data, struct seq_file *m)
{
	return 0;
}
#endif

#endif
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