From 3c935d189be9bb877c5a1110ac5fbf9c8e310658 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Tue, 31 Jul 2012 16:42:46 -0700 Subject: [PATCH] memcg: make mem_cgroup_force_empty_list() return bool mem_cgroup_force_empty_list() just returns 0 or -EBUSY and -EBUSY indicates 'you need to retry'. Make mem_cgroup_force_empty_list() return a bool to simplify the logic. [akpm@linux-foundation.org: rework mem_cgroup_force_empty_list()'s comment] Signed-off-by: KAMEZAWA Hiroyuki Cc: Michal Hocko Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 19 +++++++------------ 1 file changed, 7 insertions(+), 12 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 964786634746..a2677e0a6387 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3609,10 +3609,12 @@ unsigned long mem_cgroup_soft_limit_reclaim(struct zone *zone, int order, } /* - * This routine traverse page_cgroup in given list and drop them all. - * *And* this routine doesn't reclaim page itself, just removes page_cgroup. + * Traverse a specified page_cgroup list and try to drop them all. This doesn't + * reclaim the pages page themselves - it just removes the page_cgroups. + * Returns true if some page_cgroups were not freed, indicating that the caller + * must retry this operation. */ -static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg, +static bool mem_cgroup_force_empty_list(struct mem_cgroup *memcg, int node, int zid, enum lru_list lru) { struct mem_cgroup_per_zone *mz; @@ -3620,7 +3622,6 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg, struct list_head *list; struct page *busy; struct zone *zone; - int ret = 0; zone = &NODE_DATA(node)->node_zones[zid]; mz = mem_cgroup_zoneinfo(memcg, node, zid); @@ -3634,7 +3635,6 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg, struct page_cgroup *pc; struct page *page; - ret = 0; spin_lock_irqsave(&zone->lru_lock, flags); if (list_empty(list)) { spin_unlock_irqrestore(&zone->lru_lock, flags); @@ -3651,19 +3651,14 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *memcg, pc = lookup_page_cgroup(page); - ret = mem_cgroup_move_parent(page, pc, memcg); - - if (ret == -EBUSY || ret == -EINVAL) { + if (mem_cgroup_move_parent(page, pc, memcg)) { /* found lock contention or "pc" is obsolete. */ busy = page; cond_resched(); } else busy = NULL; } - - if (!ret && !list_empty(list)) - return -EBUSY; - return ret; + return !list_empty(list); } /* -- 2.20.1