---

yaml --- r: 130392 b: refs/heads/master c: 804b3c2 h: refs/heads/master v: v3
git-mirror · Jan 30, 2009 · 49a1a55 · 49a1a55
1 parent 32d32cd
commit 49a1a55
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Showing 3 changed files with 7 additions and 3 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1404f06565ee89e0ce04d4a5859c00b0e3a0dc8d
+refs/heads/master: 804b3c28a4e4fa1c224571bf76edb534b9c4b1ed
diff --git a/trunk/include/linux/cgroup.h b/trunk/include/linux/cgroup.h
@@ -99,6 +99,7 @@ static inline bool css_tryget(struct cgroup_subsys_state *css)
 	while (!atomic_inc_not_zero(&css->refcnt)) {
 		if (test_bit(CSS_REMOVED, &css->flags))
 			return false;
+		cpu_relax();
 	}
 	return true;
 }

diff --git a/trunk/kernel/cgroup.c b/trunk/kernel/cgroup.c
@@ -2509,7 +2509,7 @@ static int cgroup_clear_css_refs(struct cgroup *cgrp)
 	for_each_subsys(cgrp->root, ss) {
 		struct cgroup_subsys_state *css = cgrp->subsys[ss->subsys_id];
 		int refcnt;
-		do {
+		while (1) {
 			/* We can only remove a CSS with a refcnt==1 */
 			refcnt = atomic_read(&css->refcnt);
 			if (refcnt > 1) {
@@ -2523,7 +2523,10 @@ static int cgroup_clear_css_refs(struct cgroup *cgrp)
 			 * css_tryget() to spin until we set the
 			 * CSS_REMOVED bits or abort
 			 */
-		} while (atomic_cmpxchg(&css->refcnt, refcnt, 0) != refcnt);
+			if (atomic_cmpxchg(&css->refcnt, refcnt, 0) == refcnt)
+				break;
+			cpu_relax();
+		}
 	}
  done:
 	for_each_subsys(cgrp->root, ss) {