From 6d3d6aa22af30580cde0d2e23890027bb47a3544 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Wed, 10 Dec 2014 15:42:50 -0800 Subject: [PATCH] mm: memcontrol: remove synchronous stock draining code With charge reparenting, the last synchronous stock drainer left. Signed-off-by: Johannes Weiner Reviewed-by: Vladimir Davydov Acked-by: Michal Hocko Cc: David Rientjes Cc: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 46 ++++++---------------------------------------- 1 file changed, 6 insertions(+), 40 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index f90e43c1499f..3a628435f36a 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -634,8 +634,6 @@ static void disarm_static_keys(struct mem_cgroup *memcg) disarm_kmem_keys(memcg); } -static void drain_all_stock_async(struct mem_cgroup *memcg); - static struct mem_cgroup_per_zone * mem_cgroup_zone_zoneinfo(struct mem_cgroup *memcg, struct zone *zone) { @@ -2302,13 +2300,15 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) /* * Drains all per-CPU charge caches for given root_memcg resp. subtree - * of the hierarchy under it. sync flag says whether we should block - * until the work is done. + * of the hierarchy under it. */ -static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) +static void drain_all_stock(struct mem_cgroup *root_memcg) { int cpu, curcpu; + /* If someone's already draining, avoid adding running more workers. */ + if (!mutex_trylock(&percpu_charge_mutex)) + return; /* Notify other cpus that system-wide "drain" is running */ get_online_cpus(); curcpu = get_cpu(); @@ -2329,41 +2329,7 @@ static void drain_all_stock(struct mem_cgroup *root_memcg, bool sync) } } put_cpu(); - - if (!sync) - goto out; - - for_each_online_cpu(cpu) { - struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); - if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) - flush_work(&stock->work); - } -out: put_online_cpus(); -} - -/* - * Tries to drain stocked charges in other cpus. This function is asynchronous - * and just put a work per cpu for draining localy on each cpu. Caller can - * expects some charges will be back later but cannot wait for it. - */ -static void drain_all_stock_async(struct mem_cgroup *root_memcg) -{ - /* - * If someone calls draining, avoid adding more kworker runs. - */ - if (!mutex_trylock(&percpu_charge_mutex)) - return; - drain_all_stock(root_memcg, false); - mutex_unlock(&percpu_charge_mutex); -} - -/* This is a synchronous drain interface. */ -static void drain_all_stock_sync(struct mem_cgroup *root_memcg) -{ - /* called when force_empty is called */ - mutex_lock(&percpu_charge_mutex); - drain_all_stock(root_memcg, true); mutex_unlock(&percpu_charge_mutex); } @@ -2472,7 +2438,7 @@ retry: goto retry; if (!drained) { - drain_all_stock_async(mem_over_limit); + drain_all_stock(mem_over_limit); drained = true; goto retry; } -- 2.30.2