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From: Tejun Heo <tj@kernel.org>
To: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	kernel-team@fb.com
Subject: Re: [PATCH 2/2] blk-mq: Fix request handover from timeout path to normal execution
Date: Mon, 2 Apr 2018 14:10:47 -0700	[thread overview]
Message-ID: <20180402211047.GF388343@devbig577.frc2.facebook.com> (raw)
In-Reply-To: <b52fa22c-c7fa-5ebd-35cb-527786e6d08e@wdc.com>

On Mon, Apr 02, 2018 at 02:08:37PM -0700, Bart Van Assche wrote:
> On 04/02/18 12:01, Tejun Heo wrote:
> >+	 * As nothing prevents from completion happening while
> >+	 * ->aborted_gstate is set, this may lead to ignored completions
> >+	 * and further spurious timeouts.
> >+	 */
> >+	if (rq->rq_flags & RQF_MQ_TIMEOUT_RESET)
> >+		blk_mq_rq_update_aborted_gstate(rq, 0);
> 
> Hello Tejun,
> 
> Since this patch fixes one race but introduces another race, is this
> patch really an improvement?

Oh, that's not a new race.  That's the same non-critical race which
always existed.  It's just being documented.

Thanks.

-- 
tejun

  reply	other threads:[~2018-04-02 21:10 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-02 19:00 [PATCH 1/2] blk-mq: Factor out [s]rcu synchronization Tejun Heo
2018-04-02 19:01 ` [PATCH 2/2] blk-mq: Fix request handover from timeout path to normal execution Tejun Heo
2018-04-02 21:08   ` Bart Van Assche
2018-04-02 21:10     ` Tejun Heo [this message]
2018-04-02 21:31       ` Bart Van Assche
2018-04-02 21:39         ` tj
2018-04-02 21:56       ` Bart Van Assche
2018-04-02 22:01         ` tj
2018-04-02 22:09           ` Bart Van Assche
2018-04-02 22:16             ` tj
2018-04-02 22:49               ` Bart Van Assche
2018-04-02 20:48 ` [PATCH 1/2] blk-mq: Factor out [s]rcu synchronization Bart Van Assche

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