Commit 82251963 authored May 03, 2017 by Johannes Weiner Committed by Linus Torvalds May 03, 2017

mm: page_alloc: __GFP_NOWARN shouldn't suppress stall warnings

__GFP_NOWARN, which is usually added to avoid warnings from callsites
that expect to fail and have fallbacks, currently also suppresses
allocation stall warnings.  These trigger when an allocation is stuck
inside the allocator for 10 seconds or longer.

But there is no class of allocations that can get legitimately stuck in
the allocator for this long.  This always indicates a problem.

Always emit stall warnings.  Restrict __GFP_NOWARN to alloc failures.

Link: http://lkml.kernel.org/r/20170125181150.GA16398@cmpxchg.org


Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent e716f2eb

mm/page_alloc.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3751,7 +3751,7 @@ retry:

		/* Make sure we know about allocations which stall for too long */
		if (time_after(jiffies, alloc_start + stall_timeout)) {
		warn_alloc(gfp_mask, ac->nodemask,
		warn_alloc(gfp_mask & ~__GFP_NOWARN, ac->nodemask,
		"page allocation stalls for %ums, order:%u",
		jiffies_to_msecs(jiffies-alloc_start), order);
		stall_timeout += 10 * HZ;

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