mm: memcontrol: remove synchronous stock draining code
With charge reparenting, the last synchronous stock drainer left.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f90e43c..3a62843 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -634,8 +634,6 @@
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 @@
/*
* 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 @@
}
}
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 @@
goto retry;
if (!drained) {
- drain_all_stock_async(mem_over_limit);
+ drain_all_stock(mem_over_limit);
drained = true;
goto retry;
}