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Date:   Sun, 27 Feb 2022 09:16:54 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Yu Kuai <yukuai3@huawei.com>
Cc:     ming.lei@redhat.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: <YhuyBgZSS6m/Mwu6@infradead.org>
References: <20220210115637.1074927-1-yukuai3@huawei.com>
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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.