2018-06-06 05:42:14 +03:00
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// SPDX-License-Identifier: GPL-2.0
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2005-04-17 02:20:36 +04:00
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/*
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2005-11-02 06:58:39 +03:00
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* Copyright (c) 2000-2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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2005-04-17 02:20:36 +04:00
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*/
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2019-08-26 22:08:10 +03:00
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#include "xfs.h"
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2011-03-07 02:00:35 +03:00
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#include "xfs_message.h"
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2019-08-26 22:08:10 +03:00
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#include "xfs_trace.h"
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2005-04-17 02:20:36 +04:00
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void *
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2012-04-02 14:24:04 +04:00
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kmem_alloc(size_t size, xfs_km_flags_t flags)
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2005-04-17 02:20:36 +04:00
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{
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2005-10-21 11:20:48 +04:00
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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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2005-04-17 02:20:36 +04:00
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2019-08-26 22:08:10 +03:00
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trace_kmem_alloc(size, flags, _RET_IP_);
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2005-04-17 02:20:36 +04:00
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do {
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2010-01-21 00:55:30 +03:00
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ptr = kmalloc(size, lflags);
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2019-08-26 22:06:22 +03:00
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if (ptr || (flags & KM_MAYFAIL))
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2005-04-17 02:20:36 +04:00
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return ptr;
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if (!(++retries % 100))
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2011-03-07 02:00:35 +03:00
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xfs_err(NULL,
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2015-10-12 08:04:45 +03:00
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"%s(%u) possible memory allocation deadlock size %u in %s (mode:0x%x)",
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2015-10-12 07:41:29 +03:00
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current->comm, current->pid,
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2015-10-12 08:04:45 +03:00
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(unsigned int)size, __func__, lflags);
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mm: introduce memalloc_retry_wait()
Various places in the kernel - largely in filesystems - respond to a
memory allocation failure by looping around and re-trying. Some of
these cannot conveniently use __GFP_NOFAIL, for reasons such as:
- a GFP_ATOMIC allocation, which __GFP_NOFAIL doesn't work on
- a need to check for the process being signalled between failures
- the possibility that other recovery actions could be performed
- the allocation is quite deep in support code, and passing down an
extra flag to say if __GFP_NOFAIL is wanted would be clumsy.
Many of these currently use congestion_wait() which (in almost all
cases) simply waits the given timeout - congestion isn't tracked for
most devices.
It isn't clear what the best delay is for loops, but it is clear that
the various filesystems shouldn't be responsible for choosing a timeout.
This patch introduces memalloc_retry_wait() with takes on that
responsibility. Code that wants to retry a memory allocation can call
this function passing the GFP flags that were used. It will wait
however is appropriate.
For now, it only considers __GFP_NORETRY and whatever
gfpflags_allow_blocking() tests. If blocking is allowed without
__GFP_NORETRY, then alloc_page either made some reclaim progress, or
waited for a while, before failing. So there is no need for much
further waiting. memalloc_retry_wait() will wait until the current
jiffie ends. If this condition is not met, then alloc_page() won't have
waited much if at all. In that case memalloc_retry_wait() waits about
200ms. This is the delay that most current loops uses.
linux/sched/mm.h needs to be included in some files now,
but linux/backing-dev.h does not.
Link: https://lkml.kernel.org/r/163754371968.13692.1277530886009912421@noble.neil.brown.name
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Chao Yu <chao@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-01-15 01:07:14 +03:00
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memalloc_retry_wait(lflags);
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2005-04-17 02:20:36 +04:00
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} while (1);
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}
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