From: Mizuma, Masayoshi <m.mizuma@jp.fujitsu.com>
Date: Fri, 18 Apr 2014 22:07:18 +0000 (-0700)
Subject: mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()
X-Git-Tag: v3.2.59~19
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b8309464fb222570eadd3e9d4668dd1f01ad8189;p=thirdparty%2Fkernel%2Fstable.git

mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()

commit 7848a4bf51b34f41fcc9bd77e837126d99ae84e3 upstream.

soft lockup in freeing gigantic hugepage fixed in commit 55f67141a892 "mm:
hugetlb: fix softlockup when a large number of hugepages are freed." can
happen in return_unused_surplus_pages(), so let's fix it.

Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index d399f5ff5d9ca..cac2441956dc8 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1078,6 +1078,7 @@ static void return_unused_surplus_pages(struct hstate *h,
 	while (nr_pages--) {
 		if (!free_pool_huge_page(h, &node_states[N_HIGH_MEMORY], 1))
 			break;
+		cond_resched_lock(&hugetlb_lock);
 	}
 }