From: Christoph Hellwig <hch@lst.de>
To: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com, Christoph Hellwig <hch@lst.de>
Subject: Re: dm: fix blk-mq request-based DM queue initialization
Date: Thu, 30 Apr 2015 09:22:00 +0200 [thread overview]
Message-ID: <20150430072200.GB15819@lst.de> (raw)
In-Reply-To: <20150430014152.GA26430@redhat.com>
On Wed, Apr 29, 2015 at 09:41:52PM -0400, Mike Snitzer wrote:
> > I'm not quite up to speed with this area of code, but shouldn't
> > we always tear the queue fully down before trying to reinitialize it?
>
> No, the same request_queue should be used for the lifetime of a DM
> device.
>
> I'm not interested in reinitializing the queue. A DM table reload has
> no need to destroy and recreate the request_queue associated with
> the DM device. It would be bad to do so too because we actually use the
> queue across table reloads in the case of dm-multipath with no paths
> (see: map_request's handling of DM_MAPIO_REQUEUE which triggers
> dm_requeue_request).
Well - we're obviously trying to reinitialize it here and only error
out very low level with your patch. What I mean is that we shouldn't
even try to reinitialize it at a much higher level, so we don't need
this blk-mq specific hack down here.
next prev parent reply other threads:[~2015-04-30 7:22 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-25 9:23 CONFIG_DM_MQ_DEFAULT makes my kernel unhappy Christoph Hellwig
2015-04-25 15:28 ` Mike Snitzer
2015-04-25 15:37 ` Christoph Hellwig
2015-04-26 14:16 ` Christoph Hellwig
2015-04-27 15:59 ` Mike Snitzer
2015-04-27 16:03 ` Christoph Hellwig
2015-04-27 19:03 ` Mike Snitzer
2015-04-29 0:59 ` [PATCH] dm: fix blk-mq request-based DM queue initialization Mike Snitzer
2015-04-29 13:00 ` Christoph Hellwig
2015-04-30 1:41 ` Mike Snitzer
2015-04-30 7:22 ` Christoph Hellwig [this message]
2015-04-30 8:23 ` Christoph Hellwig
2015-04-30 12:47 ` Mike Snitzer
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