From: Michal Hocko <mhocko@suse.cz>
Date: Fri, 26 Oct 2012 11:37:33 +0000 (+0200)
Subject: hugetlb: do not fail in hugetlb_cgroup_pre_destroy
X-Git-Tag: firefly_0821_release~3680^2~1492^2~47^2~1
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=9d093cb10eb482adfba6ddc71a0969b78823ee8b;p=firefly-linux-kernel-4.4.55.git

hugetlb: do not fail in hugetlb_cgroup_pre_destroy

Now that pre_destroy callbacks are called from the context where neither
any task can attach the group nor any children group can be added there
is no other way to fail from hugetlb_pre_destroy.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Glauber Costa <glommer@parallels.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
---

diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index a3f358fb8a0c..dc595c6b1f55 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -159,14 +159,9 @@ static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup)
 {
 	struct hstate *h;
 	struct page *page;
-	int ret = 0, idx = 0;
+	int idx = 0;
 
 	do {
-		if (cgroup_task_count(cgroup) ||
-		    !list_empty(&cgroup->children)) {
-			ret = -EBUSY;
-			goto out;
-		}
 		for_each_hstate(h) {
 			spin_lock(&hugetlb_lock);
 			list_for_each_entry(page, &h->hugepage_activelist, lru)
@@ -177,8 +172,8 @@ static int hugetlb_cgroup_pre_destroy(struct cgroup *cgroup)
 		}
 		cond_resched();
 	} while (hugetlb_cgroup_have_usage(cgroup));
-out:
-	return ret;
+
+	return 0;
 }
 
 int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,