+ mm-page_alloc-__gfp_nowarn-shouldnt-suppress-stall-warnings.patch added to -mm tree

+ mm-page_alloc-__gfp_nowarn-shouldnt-suppress-stall-warnings.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm: page_alloc: __GFP_NOWARN shouldn't suppress stall warnings
has been added to the -mm tree.  Its filename is
     mm-page_alloc-__gfp_nowarn-shouldnt-suppress-stall-warnings.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-__gfp_nowarn-shouldnt-suppress-stall-warnings.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-page_alloc-__gfp_nowarn-shouldnt-suppress-stall-warnings.patch

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------------------------------------------------------
From: Johannes Weiner <hannes@cmpxchg.org>
Subject: 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>
---

 mm/page_alloc.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN mm/page_alloc.c~mm-page_alloc-__gfp_nowarn-shouldnt-suppress-stall-warnings mm/page_alloc.c
--- a/mm/page_alloc.c~mm-page_alloc-__gfp_nowarn-shouldnt-suppress-stall-warnings
+++ a/mm/page_alloc.c
@@ -3814,7 +3814,7 @@ 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;
_

Patches currently in -mm which might be from hannes@cmpxchg.org are

mm-fix-100%-cpu-kswapd-busyloop-on-unreclaimable-nodes.patch
mm-fix-100%-cpu-kswapd-busyloop-on-unreclaimable-nodes-fix.patch
mm-fix-check-for-reclaimable-pages-in-pf_memalloc-reclaim-throttling.patch
mm-remove-seemingly-spurious-reclaimability-check-from-laptop_mode-gating.patch
mm-remove-unnecessary-reclaimability-check-from-numa-balancing-target.patch
mm-dont-avoid-high-priority-reclaim-on-unreclaimable-nodes.patch
mm-dont-avoid-high-priority-reclaim-on-memcg-limit-reclaim.patch
mm-delete-nr_pages_scanned-and-pgdat_reclaimable.patch
revert-mm-vmscan-account-for-skipped-pages-as-a-partial-scan.patch
mm-remove-unnecessary-back-off-function-when-retrying-page-reclaim.patch
mm-memcontrol-provide-shmem-statistics.patch
mm-page_alloc-__gfp_nowarn-shouldnt-suppress-stall-warnings.patch