From a4c08e620ae40aa2883ef6cf1740786242e31339 Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Sat, 17 May 2014 23:19:25 +1000 Subject: [PATCH] memcg-mm-introduce-lowlimit-reclaim-fix mem_cgroup_reclaim_eligible -> mem_cgroup_within_guarantee follow_low_limit -> honor_memcg_guarantee and as suggested by Johannes. Cc: Johannes Weiner Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Cc: Greg Thelen Cc: Michel Lespinasse Cc: Tejun Heo Cc: Hugh Dickins Cc: Roman Gushchin Signed-off-by: Andrew Morton --- include/linux/memcontrol.h | 6 +++--- mm/memcontrol.c | 15 ++++++++------- mm/vmscan.c | 25 ++++++++++++++++--------- 3 files changed, 27 insertions(+), 19 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index bfd54264e73a..c3a53cbb88eb 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -92,7 +92,7 @@ bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg, bool task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg); -extern bool mem_cgroup_reclaim_eligible(struct mem_cgroup *memcg, +extern bool mem_cgroup_within_guarantee(struct mem_cgroup *memcg, struct mem_cgroup *root); extern struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page); @@ -291,10 +291,10 @@ static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page, return &zone->lruvec; } -static inline bool mem_cgroup_reclaim_eligible(struct mem_cgroup *memcg, +static inline bool mem_cgroup_within_guarantee(struct mem_cgroup *memcg, struct mem_cgroup *root) { - return true; + return false; } static inline struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 434ea328c9a3..96fe3a0dcba4 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2788,26 +2788,27 @@ static struct mem_cgroup *mem_cgroup_lookup(unsigned short id) } /** - * mem_cgroup_reclaim_eligible - checks whether given memcg is eligible for the - * reclaim + * mem_cgroup_within_guarantee - checks whether given memcg is within its + * memory guarantee * @memcg: target memcg for the reclaim * @root: root of the reclaim hierarchy (null for the global reclaim) * - * The given group is reclaimable if it is above its low limit and the same - * applies for all parents up the hierarchy until root (including). + * The given group is within its reclaim gurantee if it is below its low limit + * or the same applies for any parent up the hierarchy until root (including). + * Such a group might be excluded from the reclaim. */ -bool mem_cgroup_reclaim_eligible(struct mem_cgroup *memcg, +bool mem_cgroup_within_guarantee(struct mem_cgroup *memcg, struct mem_cgroup *root) { do { if (!res_counter_low_limit_excess(&memcg->res)) - return false; + return true; if (memcg == root) break; } while ((memcg = parent_mem_cgroup(memcg))); - return true; + return false; } struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) diff --git a/mm/vmscan.c b/mm/vmscan.c index 6db301f3dd5d..c0ff11ad027a 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2233,8 +2233,18 @@ static inline bool should_continue_reclaim(struct zone *zone, } } +/** + * __shrink_zone - shrinks a given zone + * + * @zone: zone to shrink + * @sc: scan control with additional reclaim parameters + * @honor_memcg_guarantee: do not reclaim memcgs which are within their memory + * guarantee + * + * Returns the number of reclaimed memcgs. + */ static unsigned __shrink_zone(struct zone *zone, struct scan_control *sc, - bool follow_low_limit) + bool honor_memcg_guarantee) { unsigned long nr_reclaimed, nr_scanned; unsigned nr_scanned_groups = 0; @@ -2254,12 +2264,9 @@ static unsigned __shrink_zone(struct zone *zone, struct scan_control *sc, do { struct lruvec *lruvec; - /* - * Memcg might be under its low limit so we have to - * skip it during the first reclaim round - */ - if (follow_low_limit && - !mem_cgroup_reclaim_eligible(memcg, root)) { + /* Memcg might be protected from the reclaim */ + if (honor_memcg_guarantee && + mem_cgroup_within_guarantee(memcg, root)) { /* * It would be more optimal to skip the memcg * subtree now but we do not have a memcg iter @@ -2307,8 +2314,8 @@ static void shrink_zone(struct zone *zone, struct scan_control *sc) if (!__shrink_zone(zone, sc, true)) { /* * First round of reclaim didn't find anything to reclaim - * because of low limit protection so try again and ignore - * the low limit this time. + * because of the memory guantees for all memcgs in the + * reclaim target so try again and ignore guarantees this time. */ __shrink_zone(zone, sc, false); } -- 2.39.2