+ mm-compaction-ignore-block-suitable-after-check-large-free-page.patch added to -mm tree

+ mm-compaction-ignore-block-suitable-after-check-large-free-page.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm/compaction: ignore block suitable after check large free page
has been added to the -mm tree.  Its filename is
     mm-compaction-ignore-block-suitable-after-check-large-free-page.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-compaction-ignore-block-suitable-after-check-large-free-page.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-compaction-ignore-block-suitable-after-check-large-free-page.patch

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------------------------------------------------------
From: Yisheng Xie <xieyisheng1@huawei.com>
Subject: mm/compaction: ignore block suitable after check large free page

By reviewing code, I find that if the migrate target is a large free page
and we ignore suitable, it may splite large target free page into smaller
block which is not good for defrag.  So move the ignore block suitable
after check large free page.

As Vlastimil pointed out in RFC version that this patch is just based on
logical analyses which might be better for future-proofing the function
and it is most likely won't have any visible effect right now, for direct
compaction shouldn't have to be called if there's a >=pageblock_order page
already available.

Link: http://lkml.kernel.org/r/1489490743-5364-1-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/compaction.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff -puN mm/compaction.c~mm-compaction-ignore-block-suitable-after-check-large-free-page mm/compaction.c
--- a/mm/compaction.c~mm-compaction-ignore-block-suitable-after-check-large-free-page
+++ a/mm/compaction.c
@@ -1003,9 +1003,6 @@ static bool suitable_migration_source(st
 static bool suitable_migration_target(struct compact_control *cc,
 							struct page *page)
 {
-	if (cc->ignore_block_suitable)
-		return true;