[3.11.y.z extended stable] Patch "mm: numa: avoid unnecessary work on the failure path" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    mm: numa: avoid unnecessary work on the failure path

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 135bd3968d5cf1a3c1c51aeb00e0c4dcf7b058c9 Mon Sep 17 00:00:00 2001
From: Mel Gorman <mgorman at suse.de>
Date: Tue, 7 Jan 2014 14:00:42 +0000
Subject: mm: numa: avoid unnecessary work on the failure path

commit eb4489f69f224356193364dc2762aa009738ca7f upstream.

If a PMD changes during a THP migration then migration aborts but the
failure path is doing more work than is necessary.

Signed-off-by: Mel Gorman <mgorman at suse.de>
Reviewed-by: Rik van Riel <riel at redhat.com>
Cc: Alex Thorlton <athorlton at sgi.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 mm/migrate.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 65bbca5..cde4b34 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1723,7 +1723,8 @@ fail_putback:
 		putback_lru_page(page);
 		mod_zone_page_state(page_zone(page),
 			 NR_ISOLATED_ANON + page_lru, -HPAGE_PMD_NR);
-		goto out_fail;
+
+		goto out_unlock;
 	}

 	/*
@@ -1797,6 +1798,7 @@ out_dropref:
 	}
 	spin_unlock(&mm->page_table_lock);

+out_unlock:
 	unlock_page(page);
 	put_page(page);
 	return 0;
--
1.8.3.2