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

[Kamal Mostafa]

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-3.8.y-queue branch of the 3.8.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-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.16.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From fd51cf6d64bd40641b0f49fa258644ed69c86ba1 Mon Sep 17 00:00:00 2001
From: Mel Gorman <mgorman at suse.de>
Date: Wed, 18 Dec 2013 17:08:39 -0800
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: Kamal Mostafa <kamal 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 6344541..5a62622 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1736,7 +1736,8 @@ 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;
 	}

 	/*
@@ -1810,6 +1811,7 @@ out_dropref:
 	}
 	spin_unlock(&mm->page_table_lock);

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