From: Yosry Ahmed <yosryahmed@google.com>
To: Tejun Heo <tj@kernel.org>, Josef Bacik <josef@toxicpanda.com>,
Jens Axboe <axboe@kernel.dk>, Zefan Li <lizefan.x@bytedance.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Roman Gushchin <roman.gushchin@linux.dev>,
Shakeel Butt <shakeelb@google.com>,
Muchun Song <muchun.song@linux.dev>,
Andrew Morton <akpm@linux-foundation.org>
Cc: Vasily Averin <vasily.averin@linux.dev>,
cgroups@vger.kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
bpf@vger.kernel.org, Yosry Ahmed <yosryahmed@google.com>
Subject: [RFC PATCH 7/7] memcg: do not modify rstat tree for zero updates
Date: Thu, 23 Mar 2023 04:00:37 +0000 [thread overview]
Message-ID: <20230323040037.2389095-8-yosryahmed@google.com> (raw)
In-Reply-To: <20230323040037.2389095-1-yosryahmed@google.com>
In some situations, we may end up calling memcg_rstat_updated() with a
value of 0, which means the stat was not actually updated. An example is
if we fail to reclaim any pages in shrink_folio_list().
Do not add the cgroup to the rstat updated tree in this case, to avoid
unnecessarily flushing it.
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
---
mm/memcontrol.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 39a9c7a978ae..7afd29399409 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -618,6 +618,9 @@ static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val)
{
unsigned int x;
+ if (!val)
+ return;
+
cgroup_rstat_updated(memcg->css.cgroup, smp_processor_id());
x = __this_cpu_add_return(stats_updates, abs(val));
--
2.40.0.rc1.284.g88254d51c5-goog
next prev parent reply other threads:[~2023-03-23 4:01 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-23 4:00 [RFC PATCH 0/7] Make rstat flushing IRQ and sleep friendly Yosry Ahmed
2023-03-23 4:00 ` [RFC PATCH 1/7] cgroup: rstat: only disable interrupts for the percpu lock Yosry Ahmed
2023-03-23 4:29 ` Shakeel Butt
2023-03-23 5:15 ` Yosry Ahmed
2023-03-23 6:33 ` Shakeel Butt
2023-03-23 13:35 ` Yosry Ahmed
2023-03-23 15:40 ` Shakeel Butt
2023-03-23 15:42 ` Yosry Ahmed
2023-03-23 15:46 ` Shakeel Butt
2023-03-23 16:09 ` Shakeel Butt
2023-03-23 16:17 ` Yosry Ahmed
2023-03-23 16:29 ` Shakeel Butt
2023-03-23 16:36 ` Yosry Ahmed
2023-03-23 16:45 ` Shakeel Butt
2023-03-23 16:51 ` Yosry Ahmed
2023-03-23 19:09 ` Shakeel Butt
2023-03-23 17:33 ` Johannes Weiner
2023-03-23 18:09 ` Yosry Ahmed
2023-03-23 18:19 ` Johannes Weiner
2023-03-24 1:39 ` Tejun Heo
2023-03-24 7:22 ` Yosry Ahmed
2023-03-24 14:12 ` Waiman Long
2023-03-24 22:50 ` Yosry Ahmed
2023-03-25 1:54 ` Tejun Heo
2023-03-25 2:17 ` Yosry Ahmed
2023-03-25 4:30 ` Shakeel Butt
2023-03-25 4:37 ` Yosry Ahmed
2023-03-25 4:46 ` Shakeel Butt
2023-03-27 23:23 ` Yosry Ahmed
2023-03-29 18:53 ` Tejun Heo
2023-03-29 19:22 ` Hugh Dickins
2023-03-29 20:00 ` Tejun Heo
2023-03-29 20:38 ` Hugh Dickins
2023-03-30 4:26 ` Yosry Ahmed
2023-03-31 1:51 ` Tejun Heo
2023-03-23 4:00 ` [RFC PATCH 2/7] memcg: do not disable interrupts when holding stats_flush_lock Yosry Ahmed
2023-03-23 4:32 ` Shakeel Butt
2023-03-23 5:16 ` Yosry Ahmed
2023-03-23 4:00 ` [RFC PATCH 3/7] cgroup: rstat: remove cgroup_rstat_flush_irqsafe() Yosry Ahmed
2023-03-23 15:43 ` Johannes Weiner
2023-03-23 15:45 ` Yosry Ahmed
2023-03-23 4:00 ` [RFC PATCH 4/7] memcg: sleep during flushing stats in safe contexts Yosry Ahmed
2023-03-23 15:56 ` Johannes Weiner
2023-03-23 16:01 ` Yosry Ahmed
2023-03-23 17:27 ` Johannes Weiner
2023-03-23 18:07 ` Yosry Ahmed
2023-03-23 19:35 ` Shakeel Butt
2023-03-23 4:00 ` [RFC PATCH 5/7] vmscan: memcg: sleep when flushing stats during reclaim Yosry Ahmed
2023-03-23 4:00 ` [RFC PATCH 6/7] workingset: memcg: sleep when flushing stats in workingset_refault() Yosry Ahmed
2023-03-23 15:50 ` Johannes Weiner
2023-03-23 16:02 ` Yosry Ahmed
2023-03-23 16:00 ` Johannes Weiner
2023-03-23 16:02 ` Yosry Ahmed
2023-03-23 4:00 ` Yosry Ahmed [this message]
2023-03-23 4:10 ` [RFC PATCH 0/7] Make rstat flushing IRQ and sleep friendly Shakeel Butt
2023-03-23 5:07 ` Yosry Ahmed
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