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Date:   Mon, 28 Feb 2022 14:11:30 +0800
From:   Ming Lei <ming.lei@redhat.com>
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Yu Kuai <yukuai3@huawei.com>, tj@kernel.org, axboe@kernel.dk,
        cgroups@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, yi.zhang@huawei.com
Subject: Re: [PATCH v9] block: cancel all throttled bios in del_gendisk()
Message-ID: <Yhxnkg0AEaj36t+a@T590>
References: <20220210115637.1074927-1-yukuai3@huawei.com>
 <YhuyBgZSS6m/Mwu6@infradead.org>
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Hi Christoph,

On Sun, Feb 27, 2022 at 09:16:54AM -0800, Christoph Hellwig wrote:
> On Thu, Feb 10, 2022 at 07:56:37PM +0800, Yu Kuai wrote:
> > Throttled bios can't be issued after del_gendisk() is done, thus
> > it's better to cancel them immediately rather than waiting for
> > throttle is done.
> > 
> > For example, if user thread is throttled with low bps while it's
> > issuing large io, and the device is deleted. The user thread will
> > wait for a long time for io to return.
> 
> FYI, this crashed left rigt and center when running xfstests with
> traces pointing to throtl_pending_timer_fn.

Can you share the exact xfstests test(fs, test)? Or panic log?

I can't reproduce it when running './check -g auto' on XFS, meantime
tracking throtl_pending_timer_fn().


Thanks,
Ming