From: Waiman Long <longman@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>,
cgroups@vger.kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, Ming Lei <ming.lei@redhat.com>
Subject: Re: [PATCH v2 2/2] blk-cgroup: Optimize blkcg_rstat_flush()
Date: Wed, 1 Jun 2022 17:25:53 -0400 [thread overview]
Message-ID: <c26f153c-304c-e109-6626-bb8b79a2e2ad@redhat.com> (raw)
In-Reply-To: <bca31669-7107-ebe4-7fbf-2449940a5cc8@redhat.com>
On 6/1/22 14:52, Waiman Long wrote:
> On 6/1/22 14:35, Tejun Heo wrote:
>
>> Can you also add an explanation on how the pending llist is synchronized
>> against blkg destructions?
>
> Sure. I will need to think about that and put a proper comment there.
I think the best way to protect against blkg destruction is to get a
percpu reference when put into lockless list and put it back when removed.
BTW, when I ran a test that continuously create and destroy containers,
the total number of blkcg's kept on increasing. There are some freeing
of blkcg's but no freeing of blkg's at all. Maybe we have a similar
dying blkcg's problem here. I will take a further look at that when I
have time.
Cheers,
Longman
next prev parent reply other threads:[~2022-06-01 21:26 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-01 16:53 [PATCH v2 1/2] blk-cgroup: Correctly free percpu iostat_cpu in blkg on error exit Waiman Long
2022-06-01 16:53 ` [PATCH v2 2/2] blk-cgroup: Optimize blkcg_rstat_flush() Waiman Long
2022-06-01 17:48 ` Tejun Heo
2022-06-01 18:15 ` Waiman Long
2022-06-01 18:35 ` Tejun Heo
2022-06-01 18:52 ` Waiman Long
2022-06-01 21:25 ` Waiman Long [this message]
2022-06-01 21:28 ` Tejun Heo
2022-06-01 21:32 ` Waiman Long
2022-06-02 1:52 ` kernel test robot
2022-06-01 17:48 ` [PATCH v2 1/2] blk-cgroup: Correctly free percpu iostat_cpu in blkg on error exit Tejun Heo
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