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Sender: Tejun Heo <htejun@gmail.com>
Date:   Tue, 13 Dec 2022 09:30:59 -1000
From:   Tejun Heo <tj@kernel.org>
To:     Waiman Long <longman@redhat.com>
Cc:     Jens Axboe <axboe@kernel.dk>, Josef Bacik <josef@toxicpanda.com>,
        Zefan Li <lizefan.x@bytedance.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        cgroups@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Michal =?iso-8859-1?Q?Koutn=FD?= <mkoutny@suse.com>,
        "Dennis Zhou (Facebook)" <dennisszhou@gmail.com>
Subject: Re: [PATCH-block v3 2/2] blk-cgroup: Flush stats at blkgs
 destruction path
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References: <20221213184446.50181-1-longman@redhat.com>
 <20221213184446.50181-3-longman@redhat.com>
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On Tue, Dec 13, 2022 at 01:44:46PM -0500, Waiman Long wrote:
> +	/*
> +	 * Flush all the non-empty percpu lockless lists so as to release
> +	 * the blkg references held by those lists which, in turn, may
> +	 * allow the blkgs to be freed and release their references to
> +	 * blkcg speeding up its freeing.
> +	 */

Can you mention the possible deadlock explicitly? This sounds more like an
optimization.

Thanks.

-- 
tejun