Patch "mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask" has been added to the 4.6-stable tree

Patch "mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask" has been added to the 4.6-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask

to the 4.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mm-slb-add-__gfp_atomic-to-the-gfp-reclaim-mask.patch
and it can be found in the queue-4.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From e838a45f9392a5bd2be1cd3ab0b16ae85857461c Mon Sep 17 00:00:00 2001
From: Mel Gorman <mgorman@techsingularity.net>
Date: Fri, 24 Jun 2016 14:49:37 -0700
Subject: mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask

From: Mel Gorman <mgorman@techsingularity.net>

commit e838a45f9392a5bd2be1cd3ab0b16ae85857461c upstream.

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>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/mm/internal.h
+++ b/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 stable-queue which might be from mgorman@techsingularity.net are

queue-4.6/mm-compaction-abort-free-scanner-if-split-fails.patch
queue-4.6/sched-debug-fix-deadlock-when-enabling-sched-events.patch
queue-4.6/mm-compaction-prevent-vm_bug_on-when-terminating-freeing-scanner.patch
queue-4.6/mm-meminit-always-return-a-valid-node-from-early_pfn_to_nid.patch
queue-4.6/mm-meminit-ensure-node-is-online-before-checking-whether-pages-are-uninitialised.patch
queue-4.6/mm-slb-add-__gfp_atomic-to-the-gfp-reclaim-mask.patch