From: zhenwei.pi <zhenwei.pi@youruncloud.com>
Date: Mon, 10 Jul 2017 22:49:47 +0000 (-0700)
Subject: mm/balloon_compaction.c: enqueue zero page to balloon device
X-Git-Tag: v4.13-rc1~62^2~63
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=bb01b64cfab7c22f3848cb73dc0c2b46b8d38499;p=linux.git

mm/balloon_compaction.c: enqueue zero page to balloon device

presently pages in the balloon device have random value, and these pages
will be scanned by ksmd on the host.  They usually cannot be merged.
Enqueue zero pages will resolve this problem.

Link: http://lkml.kernel.org/r/1498698637-26389-1-git-send-email-zhenwei.pi@youruncloud.com
Signed-off-by: zhenwei.pi <zhenwei.pi@youruncloud.com>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
index da91df50ba31..9075aa54e955 100644
--- a/mm/balloon_compaction.c
+++ b/mm/balloon_compaction.c
@@ -24,7 +24,7 @@ struct page *balloon_page_enqueue(struct balloon_dev_info *b_dev_info)
 {
 	unsigned long flags;
 	struct page *page = alloc_page(balloon_mapping_gfp_mask() |
-					__GFP_NOMEMALLOC | __GFP_NORETRY);
+				__GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_ZERO);
 	if (!page)
 		return NULL;