The patch titled
Subject: mm,ksm: add __GFP_HIGH to the allocation in alloc_stable_node()
has been removed from the -mm tree. Its filename was
mmksm-add-__gfp_high-to-the-allocation-in-alloc_stable_node.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: zhong jiang <zhongjiang@xxxxxxxxxx>
Subject: mm,ksm: add __GFP_HIGH to the allocation in alloc_stable_node()
According to Hugh's suggestion, alloc_stable_node() with GFP_KERNEL can in
rare cases cause a hung task warning.
At present, if alloc_stable_node() allocation fails, two break_cows may
want to allocate a couple of pages, and the issue will come up when free
memory is under pressure.
We fix it by adding __GFP_HIGH to GFP, to grant access to memory reserves,
increasing the likelihood of allocation success.
[akpm@xxxxxxxxxxxxxxxxxxxx: tweak comment]
Link: http://lkml.kernel.org/r/1474354484-58233-1-git-send-email-zhongjiang@xxxxxxxxxx
Signed-off-by: zhong jiang <zhongjiang@xxxxxxxxxx>
Suggested-by: Hugh Dickins <hughd@xxxxxxxxxx>
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/ksm.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff -puN mm/ksm.c~mmksm-add-__gfp_high-to-the-allocation-in-alloc_stable_node mm/ksm.c
--- a/mm/ksm.c~mmksm-add-__gfp_high-to-the-allocation-in-alloc_stable_node
+++ a/mm/ksm.c
@@ -299,7 +299,12 @@ static inline void free_rmap_item(struct
static inline struct stable_node *alloc_stable_node(void)
{
- return kmem_cache_alloc(stable_node_cache, GFP_KERNEL);
+ /*
+ * The allocation can take too long with GFP_KERNEL when memory is under
+ * pressure, which may lead to hung task warnings. Adding __GFP_HIGH
+ * grants access to memory reserves, helping to avoid this problem.
+ */
+ return kmem_cache_alloc(stable_node_cache, GFP_KERNEL | __GFP_HIGH);
}
static inline void free_stable_node(struct stable_node *stable_node)
_
Patches currently in -mm which might be from zhongjiang@xxxxxxxxxx are
mm-page_owner-align-with-pageblock_nr-pages.patch
mm-walk-the-zone-in-pageblock_nr_pages-steps.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
