From: Christoph Hellwig <hch@infradead.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: Dave Chinner <david@fromorbit.com>, linux-kernel@vger.kernel.org
Subject: Re: [Regression x2, 3.13-git] virtio block mq hang, iostat busted on virtio devices
Date: Wed, 20 Nov 2013 00:04:40 -0800 [thread overview]
Message-ID: <20131120080440.GA13147@infradead.org> (raw)
In-Reply-To: <528BDB97.8090608@kernel.dk>
On Tue, Nov 19, 2013 at 02:43:51PM -0700, Jens Axboe wrote:
> No, the nr_requests isn't actually relevant in the blk-mq context, the
> driver sets its own depth. For the above, it's 64 normal commands, and 2
> reserved. The reserved would be for a flush, for instance. If someone
> attempts to queue more than the allocated number of requests, it'll stop
> the blk-mq queue and kick things into gear on the virtio side. Then when
> requests complete, we start the queue again.
Btw, any reason we lowerered the queue depth from 128 to 64 in
virtio-blk?
next prev parent reply other threads:[~2013-11-20 8:04 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-19 8:02 [Regression x2, 3.13-git] virtio block mq hang, iostat busted on virtio devices Dave Chinner
2013-11-19 10:36 ` Christoph Hellwig
2013-11-19 16:05 ` Jens Axboe
2013-11-19 16:09 ` Christoph Hellwig
2013-11-19 16:16 ` Jens Axboe
2013-11-19 21:30 ` Dave Chinner
2013-11-19 21:40 ` Jens Axboe
2013-11-19 20:15 ` Jens Axboe
2013-11-19 21:20 ` Jens Axboe
2013-11-19 21:34 ` Dave Chinner
2013-11-19 21:43 ` Jens Axboe
2013-11-19 22:42 ` Jens Axboe
2013-11-19 22:51 ` Jens Axboe
2013-11-19 23:23 ` Dave Chinner
2013-11-19 23:59 ` Jens Axboe
2013-11-20 0:08 ` Jens Axboe
2013-11-20 1:44 ` Shaohua Li
2013-11-20 1:54 ` Jens Axboe
2013-11-20 2:02 ` Jens Axboe
2013-11-20 2:53 ` Dave Chinner
2013-11-20 3:12 ` Jens Axboe
2013-11-20 8:07 ` Christoph Hellwig
2013-11-20 16:21 ` Jens Axboe
2013-11-20 8:04 ` Christoph Hellwig [this message]
2013-11-20 16:20 ` Jens Axboe
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