From: Tejun Heo <tj@kernel.org>
To: Julian Sun <sunjunchao@bytedance.com>
Cc: linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org,
linux-mm@kvack.org, viro@zeniv.linux.org.uk, brauner@kernel.org,
jack@suse.cz, hannes@cmpxchg.org, mhocko@kernel.org,
roman.gushchin@linux.dev, shakeel.butt@linux.dev,
muchun.song@linux.dev, axboe@kernel.dk
Subject: Re: [External] Re: [PATCH] memcg: Don't wait writeback completion when release memcg.
Date: Mon, 25 Aug 2025 08:53:07 -1000 [thread overview]
Message-ID: <aKyxE6QOR_PtQ0mT@slm.duckdns.org> (raw)
In-Reply-To: <CAHSKhtc3Y-c5aoycj06V-8WwOeofXt5EHGkr4GLrU9VJt_ckmw@mail.gmail.com>
Hello,
On Tue, Aug 26, 2025 at 01:45:44AM +0800, Julian Sun wrote:
...
> Sorry for having misunderstood what you meant before. I’m afraid that
> init_wait_func() cannot work the same way. Because calling
> init_wait_func() presupposes that we are preparing to wait for an
> event(like wb_wait_completion()), but waiting for such an event might
> lead to a hung task.
>
> Please correct me if I'm wrong.
Using init_wait_func() does not require someone waiting for it. AFAICS, you
should be able to do the same thing that you did - allocating the done
entries individually and freeing them when the done count reaches zero
without anyone waiting for it. waitq doesn't really make many assumptions
about how it's used - when you call wake_up() on it, it just walks the
queued entries and invoke the callbacks there.
Thanks.
--
tejun
next prev parent reply other threads:[~2025-08-25 18:53 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-20 11:19 [PATCH 0/3] memcg, writeback: Don't wait writeback completion Julian Sun
2025-08-20 11:19 ` [PATCH 1/3] writeback: Rename wb_writeback_work->auto_free to free_work Julian Sun
2025-08-20 11:19 ` [PATCH] writeback: Add wb_writeback_work->free_done Julian Sun
2025-08-20 11:19 ` [PATCH] memcg: Don't wait writeback completion when release memcg Julian Sun
2025-08-20 20:58 ` Tejun Heo
2025-08-21 2:30 ` [External] " Julian Sun
2025-08-21 16:59 ` Tejun Heo
2025-08-21 18:00 ` Julian Sun
2025-08-21 18:16 ` Julian Sun
2025-08-21 19:01 ` Tejun Heo
2025-08-22 8:22 ` Julian Sun
2025-08-22 17:56 ` Tejun Heo
2025-08-23 6:18 ` Julian Sun
2025-08-23 8:08 ` Giorgi Tchankvetadze
2025-08-23 8:22 ` Julian Sun
2025-08-23 14:08 ` Giorgi Tchankvetadze
2025-08-23 15:17 ` Julian Sun
2025-08-25 17:45 ` Julian Sun
2025-08-25 18:53 ` Tejun Heo [this message]
2025-08-25 19:06 ` Julian Sun
2025-08-25 10:13 ` Jan Kara
2025-08-25 12:08 ` Julian Sun
2025-08-25 18:57 ` [External] " Tejun Heo
2025-08-20 12:16 ` [PATCH 0/3] memcg, writeback: Don't wait writeback completion Giorgi Tchankvetadze
2025-08-21 2:37 ` [External] " Julian Sun
2025-08-22 9:29 ` Giorgi Tchankvetadze
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