From 67c58ce60024b9b3d9cf203da994bf265aa7e369 Mon Sep 17 00:00:00 2001
From: David Rientjes <rientjes@google.com>
Date: Thu, 3 Apr 2014 14:47:23 -0700
Subject: [PATCH 1/1] mm, compaction: ignore pageblock skip when manually
 invoking compaction

commit 91ca9186484809c57303b33778d841cc28f696ed upstream.

The cached pageblock hint should be ignored when triggering compaction
through /proc/sys/vm/compact_memory so all eligible memory is isolated.
Manually invoking compaction is known to be expensive, there's no need
to skip pageblocks based on heuristics (mainly for debugging).

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 mm/compaction.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/compaction.c b/mm/compaction.c
index 951209b..5e38e57 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1193,6 +1193,7 @@ static void compact_node(int nid)
 	struct compact_control cc = {
 		.order = -1,
 		.sync = true,
+		.ignore_skip_hint = true,
 	};
 
 	__compact_pgdat(NODE_DATA(nid), &cc);
-- 
2.7.4