From bc2f2e7ffe5b6292c74ee1206d6ca303e13886b2 Mon Sep 17 00:00:00 2001 From: Vladimir Davydov Date: Wed, 10 Dec 2014 15:43:40 -0800 Subject: [PATCH] memcg: simplify unreclaimable groups handling in soft limit reclaim If we fail to reclaim anything from a cgroup during a soft reclaim pass we want to get the next largest cgroup exceeding its soft limit. To achieve this, we should obviously remove the current group from the tree and then pick the largest group. Currently we have a weird loop instead. Let's simplify it. Signed-off-by: Vladimir Davydov Acked-by: Johannes Weiner Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 26 ++++---------------------- 1 file changed, 4 insertions(+), 22 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 3a628435f36a..975207a9cc65 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3518,34 +3518,16 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, nr_reclaimed += reclaimed; *total_scanned += nr_scanned; spin_lock_irq(&mctz->lock); + __mem_cgroup_remove_exceeded(mz, mctz); /* * If we failed to reclaim anything from this memory cgroup * it is time to move on to the next cgroup */ next_mz = NULL; - if (!reclaimed) { - do { - /* - * Loop until we find yet another one. - * - * By the time we get the soft_limit lock - * again, someone might have aded the - * group back on the RB tree. Iterate to - * make sure we get a different mem. - * mem_cgroup_largest_soft_limit_node returns - * NULL if no other cgroup is present on - * the tree - */ - next_mz = - __mem_cgroup_largest_soft_limit_node(mctz); - if (next_mz == mz) - css_put(&next_mz->memcg->css); - else /* next_mz == NULL or other memcg */ - break; - } while (1); - } - __mem_cgroup_remove_exceeded(mz, mctz); + if (!reclaimed) + next_mz = __mem_cgroup_largest_soft_limit_node(mctz); + excess = soft_limit_excess(mz->memcg); /* * One school of thought says that we should not add