Commit 6d3d6aa2 authored by Johannes Weiner's avatar Johannes Weiner Committed by Linus Torvalds
Browse files

mm: memcontrol: remove synchronous stock draining code 



With charge reparenting, the last synchronous stock drainer left.

Signed-off-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: default avatarVladimir Davydov <vdavydov@parallels.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b2052564

mm/memcontrol.c

+6 −40
Original line number Diff line number Diff line
@@ -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 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask, 
		goto retry;



	if (!drained) {

		drain_all_stock_async(mem_over_limit);

		drain_all_stock(mem_over_limit);

		drained = true;

		goto retry;

	}