This is a note to let you know that I've just added the patch titled
mm: shmem: avoid atomic operation during shmem_getpage_gfp
to the 3.14-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-shmem-avoid-atomic-operation-during-shmem_getpage_gfp.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 07a427884348d38a6fd56fa4d78249c407196650 Mon Sep 17 00:00:00 2001
From: Mel Gorman <mgorman@xxxxxxx>
Date: Wed, 4 Jun 2014 16:10:24 -0700
Subject: mm: shmem: avoid atomic operation during shmem_getpage_gfp
From: Mel Gorman <mgorman@xxxxxxx>
commit 07a427884348d38a6fd56fa4d78249c407196650 upstream.
shmem_getpage_gfp uses an atomic operation to set the SwapBacked field
before it's even added to the LRU or visible. This is unnecessary as what
could it possible race against? Use an unlocked variant.
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Rik van Riel <riel@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Theodore Ts'o <tytso@xxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
include/linux/page-flags.h | 1 +
mm/shmem.c | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -208,6 +208,7 @@ PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinn
PAGEFLAG(SavePinned, savepinned); /* Xen */
PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved)
PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked)
+ __SETPAGEFLAG(SwapBacked, swapbacked)
__PAGEFLAG(SlobFree, slob_free)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1140,7 +1140,7 @@ repeat:
goto decused;
}
- SetPageSwapBacked(page);
+ __SetPageSwapBacked(page);
__set_page_locked(page);
error = mem_cgroup_cache_charge(page, current->mm,
gfp & GFP_RECLAIM_MASK);
Patches currently in stable-queue which might be from mgorman@xxxxxxx are
queue-3.14/mm-page_alloc-use-jump-labels-to-avoid-checking-number_of_cpusets.patch
queue-3.14/mm-page_alloc-do-not-treat-a-zone-that-cannot-be-used-for-dirty-pages-as-full.patch
queue-3.14/mm-non-atomically-mark-page-accessed-during-page-cache-allocation-where-possible.patch
queue-3.14/mm-page_alloc-convert-hot-cold-parameter-and-immediate-callers-to-bool.patch
queue-3.14/mm-page_alloc-only-check-the-zone-id-check-if-pages-are-buddies.patch
queue-3.14/mm-page_alloc-only-check-the-alloc-flags-and-gfp_mask-for-dirty-once.patch
queue-3.14/mm-page_alloc-do-not-update-zlc-unless-the-zlc-is-active.patch
queue-3.14/mm-swap.c-clean-up-lru_cache_add-functions.patch
queue-3.14/mm-page_alloc-take-the-alloc_no_watermark-check-out-of-the-fast-path.patch
queue-3.14/fs-buffer-do-not-use-unnecessary-atomic-operations-when-discarding-buffers.patch
queue-3.14/mm-do-not-use-atomic-operations-when-releasing-pages.patch
queue-3.14/mm-page_alloc-reduce-number-of-times-page_to_pfn-is-called.patch
queue-3.14/mm-page_alloc-use-unsigned-int-for-order-in-more-places.patch
queue-3.14/mm-avoid-unnecessary-atomic-operations-during-end_page_writeback.patch
queue-3.14/mm-shmem-avoid-atomic-operation-during-shmem_getpage_gfp.patch
queue-3.14/mm-do-not-use-unnecessary-atomic-operations-when-adding-pages-to-the-lru.patch
queue-3.14/include-linux-jump_label.h-expose-the-reference-count.patch
queue-3.14/mm-page_alloc-calculate-classzone_idx-once-from-the.patch
queue-3.14/mm-page_alloc-lookup-pageblock-migratetype-with-irqs-enabled-during-free.patch
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