+ mm-slaub-add-__gfp_atomic-to-the-gfp-reclaim-mask.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask
has been added to the -mm tree.  Its filename is
     mm-slaub-add-__gfp_atomic-to-the-gfp-reclaim-mask.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-slaub-add-__gfp_atomic-to-the-gfp-reclaim-mask.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-slaub-add-__gfp_atomic-to-the-gfp-reclaim-mask.patch

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------------------------------------------------------
From: Mel Gorman <mgorman@techsingularity.net>
Subject: mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask

Commit d0164adc89f6 ("mm, page_alloc: distinguish between being unable to
sleep, unwilling to sleep and avoiding waking kswapd") modified __GFP_WAIT
to explicitly identify the difference between atomic callers and those
that were unwilling to sleep.  Later the definition was removed entirely.

The GFP_RECLAIM_MASK is the set of flags that affect watermark checking
and reclaim behaviour but __GFP_ATOMIC was never added. Without it, atomic
users of the slab allocator strip the __GFP_ATOMIC flag and cannot access
the page allocator atomic reserves.  This patch addresses the problem.

The user-visible impact depends on the workload but potentially atomic
allocations unnecessarily fail without this path.

Link: http://lkml.kernel.org/r/20160610093832.GK2527@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Marcin Wojtas <mw@semihalf.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>	[4.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/internal.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff -puN mm/internal.h~mm-slaub-add-__gfp_atomic-to-the-gfp-reclaim-mask mm/internal.h
--- a/mm/internal.h~mm-slaub-add-__gfp_atomic-to-the-gfp-reclaim-mask
+++ a/mm/internal.h
@@ -24,7 +24,8 @@
  */
 #define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
 			__GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
-			__GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC)
+			__GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\
+			__GFP_ATOMIC)
 
 /* The GFP flags allowed during early boot */
 #define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
_

Patches currently in -mm which might be from mgorman@techsingularity.net are

mm-slaub-add-__gfp_atomic-to-the-gfp-reclaim-mask.patch