From 18651a171d0cdfb950fef46c49a67ac5a9e62f05 Mon Sep 17 00:00:00 2001
From: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
Date: Tue, 31 Jul 2012 16:41:44 -0700
Subject: [PATCH] --- yaml --- r: 320759 b: refs/heads/master c:
 3fb5c298b04eb6e472f8db1f0fb472749d30041c h: refs/heads/master i:   320757:
 e376cd17ae19507bd4742177761709f4d5e33eda   320755:
 a0eb9565e007dbb0b2b1c770b762e6aaa2c8ba55   320751:
 faf6bc041cd3e313f5d9eebda751bb8395c100b5 v: v3

---
 [refs]                | 2 +-
 trunk/mm/swap_state.c | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 3f62627e1617..7577be2087f0 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a7d6f529fe1d96a477614eb93f40213d133029e6
+refs/heads/master: 3fb5c298b04eb6e472f8db1f0fb472749d30041c
diff --git a/trunk/mm/swap_state.c b/trunk/mm/swap_state.c
index 4c5ff7f284d9..c85b5590cccd 100644
--- a/trunk/mm/swap_state.c
+++ b/trunk/mm/swap_state.c
@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/pagemap.h>
 #include <linux/backing-dev.h>
+#include <linux/blkdev.h>
 #include <linux/pagevec.h>
 #include <linux/migrate.h>
 #include <linux/page_cgroup.h>
@@ -376,6 +377,7 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
 	unsigned long offset = swp_offset(entry);
 	unsigned long start_offset, end_offset;
 	unsigned long mask = (1UL << page_cluster) - 1;
+	struct blk_plug plug;
 
 	/* Read a page_cluster sized and aligned cluster around offset. */
 	start_offset = offset & ~mask;
@@ -383,6 +385,7 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
 	if (!start_offset)	/* First page is swap header. */
 		start_offset++;
 
+	blk_start_plug(&plug);
 	for (offset = start_offset; offset <= end_offset ; offset++) {
 		/* Ok, do the async read-ahead now */
 		page = read_swap_cache_async(swp_entry(swp_type(entry), offset),
@@ -391,6 +394,8 @@ struct page *swapin_readahead(swp_entry_t entry, gfp_t gfp_mask,
 			continue;
 		page_cache_release(page);
 	}
+	blk_finish_plug(&plug);
+
 	lru_add_drain();	/* Push any new pages onto the LRU now */
 	return read_swap_cache_async(entry, gfp_mask, vma, addr);
 }