[Devel] [PATCH rh7 7/8] mm/mem_cgroup_iter: Cleanup mem_cgroup_iter_load()

[Konstantin Khorenko]

No functional changes here.

https://jira.sw.ru/browse/PSBM-123655

Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
---
 mm/memcontrol.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 39b3350eddf9..62bc824adb53 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1646,23 +1646,20 @@ mem_cgroup_iter_load(struct mem_cgroup_reclaim_iter *iter,
 	 * offlining.  The RCU lock ensures the object won't be
 	 * released, tryget will fail if we lost the race.
 	 */
-retry:
-	seq = read_seqbegin(&iter->last_visited_lock);
+	do {
+		seq = read_seqbegin(&iter->last_visited_lock);
 		position = READ_ONCE(iter->last_visited);
+	} while (read_seqretry(&iter->last_visited_lock, seq));
 
-		if (read_seqretry(&iter->last_visited_lock, seq))
-			goto retry;
+	/*
+	 * We cannot take a reference to root because we might race
+	 * with root removal and returning NULL would end up in
+	 * an endless loop on the iterator user level when root
+	 * would be returned all the time.
+	 */
+	if (position && position != root && !css_tryget(&position->css))
+		position = NULL;
 
-		/*
-		 * We cannot take a reference to root because we might race
-		 * with root removal and returning NULL would end up in
-		 * an endless loop on the iterator user level when root
-		 * would be returned all the time.
-		*/
-		if (position && position != root &&
-				!css_tryget(&position->css))
-
-			position = NULL;
 	return position;
 }
 
-- 
2.24.3