From: Christoph Hellwig <hch@lst.de>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Jan Kara <jack@suse.cz>, Christoph Hellwig <hch@lst.de>,
Jens Axboe <axboe@kernel.dk>,
"Darrick J . Wong" <djwong@kernel.org>,
linux-block@vger.kernel.org, Ming Lei <ming.lei@redhat.com>,
syzbot+6479585dfd4dedd3f7e1@syzkaller.appspotmail.com
Subject: Re: [PATCH 8/8] loop: don't destroy lo->workqueue in __loop_clr_fd
Date: Tue, 22 Mar 2022 12:10:17 +0100 [thread overview]
Message-ID: <20220322111017.GB28931@lst.de> (raw)
In-Reply-To: <dd4e3821-24cf-8b65-4851-f90b395a4557@I-love.SAKURA.ne.jp>
On Wed, Mar 16, 2022 at 10:24:20PM +0900, Tetsuo Handa wrote:
> Since this WQ is invoked when flushing data to disk, this WQ had better use
> WQ_MEM_RECLAIM flag when creating. A WQ created with WQ_MEM_RECLAIM flag has
> at least one "struct task_struct" in order to guarantee forward progress, but
> results in consuming more kernel resources. Therefore, it is preferable to
> destroy the WQ when clearing unbinding a loop device from a backing file.
Whіch then gets us into lock dependency problems. A previously used
but lingering around device will use some resources, so what? If you
care about the least used resources the only way to get there is to
destroy the device.
next prev parent reply other threads:[~2022-03-22 11:10 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-16 8:45 yet another approach to fix the loop lock order inversions v3 Christoph Hellwig
2022-03-16 8:45 ` [PATCH 1/8] loop: de-duplicate the idle worker freeing code Christoph Hellwig
2022-03-16 8:45 ` [PATCH 2/8] loop: initialize the worker tracking fields once Christoph Hellwig
2022-03-16 9:26 ` Chaitanya Kulkarni
2022-03-16 8:45 ` [PATCH 3/8] loop: remove the racy bd_inode->i_mapping->nrpages asserts Christoph Hellwig
2022-03-16 10:24 ` Jan Kara
2022-03-16 8:45 ` [PATCH 4/8] loop: don't freeze the queue in lo_release Christoph Hellwig
2022-03-16 8:45 ` [PATCH 5/8] loop: only freeze the queue in __loop_clr_fd when needed Christoph Hellwig
2022-03-16 8:45 ` [PATCH 6/8] loop: implement ->free_disk Christoph Hellwig
2022-03-16 10:30 ` Jan Kara
2022-03-16 8:45 ` [PATCH 7/8] loop: remove lo_refcount and avoid lo_mutex in ->open / ->release Christoph Hellwig
2022-03-16 11:22 ` Jan Kara
2022-03-16 13:14 ` Tetsuo Handa
2022-03-16 14:38 ` Jan Kara
2022-03-22 11:09 ` Christoph Hellwig
2022-03-23 12:18 ` Jan Kara
2022-03-23 13:09 ` Tetsuo Handa
2022-03-16 8:45 ` [PATCH 8/8] loop: don't destroy lo->workqueue in __loop_clr_fd Christoph Hellwig
2022-03-16 11:25 ` Jan Kara
2022-03-16 13:24 ` Tetsuo Handa
2022-03-22 11:10 ` Christoph Hellwig [this message]
2022-03-22 12:42 ` Tetsuo Handa
2022-03-23 0:06 ` Tetsuo Handa
2022-03-16 10:59 ` yet another approach to fix the loop lock order inversions v3 Tetsuo Handa
2022-03-22 11:12 ` Christoph Hellwig
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