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From: Jens Axboe <axboe@kernel.dk>
To: Ming Lei <ming.lei@redhat.com>
Cc: linux-block@vger.kernel.org, stable@vger.kernel.org,
	Omar Sandoval <osandov@fb.com>
Subject: Re: [PATCH V2] blk-mq: avoid to starve tag allocation after allocation process migrates
Date: Tue, 22 May 2018 14:20:37 -0600	[thread overview]
Message-ID: <9ea0bf13-8891-0214-d735-2088827b2937@kernel.dk> (raw)
In-Reply-To: <20180519074406.6045-1-ming.lei@redhat.com>

On 5/19/18 1:44 AM, Ming Lei wrote:
> When the allocation process is scheduled back and the mapped hw queue is
> changed, do one extra wake up on orignal queue for compensating wake up
> miss, so other allocations on the orignal queue won't be starved.
> 
> This patch fixes one request allocation hang issue, which can be
> triggered easily in case of very low nr_request.

Can you explain what the actual bug is? The commit message doesn't
really say, it just explains what the code change does. What wake up
miss?

-- 
Jens Axboe

  reply	other threads:[~2018-05-22 20:20 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-19  7:44 [PATCH V2] blk-mq: avoid to starve tag allocation after allocation process migrates Ming Lei
2018-05-22 20:20 ` Jens Axboe [this message]
2018-05-23  0:22   ` Ming Lei
2018-05-23  3:35     ` Jens Axboe
2018-05-23 17:40 ` Omar Sandoval
2018-05-24  2:20   ` Ming Lei

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