From: Roman Gushchin <guroan@gmail.com>
To: linux-mm@kvack.org, kernel-team@fb.com
Cc: linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
Rik van Riel <riel@surriel.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>, Roman Gushchin <guro@fb.com>
Subject: [PATCH v2 4/6] mm: release per-node memcg percpu data prematurely
Date: Tue, 12 Mar 2019 15:34:01 -0700 [thread overview]
Message-ID: <20190312223404.28665-5-guro@fb.com> (raw)
In-Reply-To: <20190312223404.28665-1-guro@fb.com>
Similar to memcg-level statistics, per-node data isn't expected
to be hot after cgroup removal. Switching over to atomics and
prematurely releasing percpu data helps to reduce the memory
footprint of dying cgroups.
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
include/linux/memcontrol.h | 1 +
mm/memcontrol.c | 24 +++++++++++++++++++++++-
2 files changed, 24 insertions(+), 1 deletion(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 569337514230..f296693d102b 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -127,6 +127,7 @@ struct mem_cgroup_per_node {
struct lruvec lruvec;
struct lruvec_stat __rcu /* __percpu */ *lruvec_stat_cpu;
+ struct lruvec_stat __percpu *lruvec_stat_cpu_offlined;
atomic_long_t lruvec_stat[NR_VM_NODE_STAT_ITEMS];
unsigned long lru_zone_size[MAX_NR_ZONES][NR_LRU_LISTS];
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index efd5bc131a38..1b5fe826d6d0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4460,7 +4460,7 @@ static void free_mem_cgroup_per_node_info(struct mem_cgroup *memcg, int node)
if (!pn)
return;
- free_percpu(pn->lruvec_stat_cpu);
+ WARN_ON_ONCE(pn->lruvec_stat_cpu != NULL);
kfree(pn);
}
@@ -4616,7 +4616,17 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css)
static void percpu_rcu_free(struct rcu_head *rcu)
{
struct mem_cgroup *memcg = container_of(rcu, struct mem_cgroup, rcu);
+ int node;
+
+ for_each_node(node) {
+ struct mem_cgroup_per_node *pn = memcg->nodeinfo[node];
+ if (!pn)
+ continue;
+
+ free_percpu(pn->lruvec_stat_cpu_offlined);
+ WARN_ON_ONCE(pn->lruvec_stat_cpu != NULL);
+ }
free_percpu(memcg->vmstats_percpu_offlined);
WARN_ON_ONCE(memcg->vmstats_percpu);
@@ -4625,6 +4635,18 @@ static void percpu_rcu_free(struct rcu_head *rcu)
static void mem_cgroup_offline_percpu(struct mem_cgroup *memcg)
{
+ int node;
+
+ for_each_node(node) {
+ struct mem_cgroup_per_node *pn = memcg->nodeinfo[node];
+
+ if (!pn)
+ continue;
+
+ pn->lruvec_stat_cpu_offlined = (struct lruvec_stat __percpu *)
+ rcu_dereference(pn->lruvec_stat_cpu);
+ rcu_assign_pointer(pn->lruvec_stat_cpu, NULL);
+ }
memcg->vmstats_percpu_offlined = (struct memcg_vmstats_percpu __percpu*)
rcu_dereference(memcg->vmstats_percpu);
rcu_assign_pointer(memcg->vmstats_percpu, NULL);
--
2.20.1
next prev parent reply other threads:[~2019-03-12 22:34 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-12 22:33 [PATCH v2 0/6] mm: reduce the memory footprint of dying memory cgroups Roman Gushchin
2019-03-12 22:33 ` [PATCH v2 1/6] mm: prepare to premature release of memcg->vmstats_percpu Roman Gushchin
2019-03-12 22:33 ` [PATCH v2 2/6] mm: prepare to premature release of per-node lruvec_stat_cpu Roman Gushchin
2019-03-12 22:34 ` [PATCH v2 3/6] mm: release memcg percpu data prematurely Roman Gushchin
2019-03-12 22:34 ` Roman Gushchin [this message]
2019-03-12 22:34 ` [PATCH v2 5/6] mm: flush memcg percpu stats and events before releasing Roman Gushchin
2019-03-13 16:00 ` Johannes Weiner
2019-03-13 18:23 ` Roman Gushchin
2019-03-12 22:34 ` [PATCH 5/5] mm: spill " Roman Gushchin
2019-03-12 22:34 ` [PATCH v2 6/6] mm: refactor memcg_hotplug_cpu_dead() to use memcg_flush_offline_percpu() Roman Gushchin
2019-03-13 16:07 ` Johannes Weiner
2019-03-13 18:23 ` Roman Gushchin
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