From: hch@infradead.org (Christoph Hellwig)
Subject: [PATCH] nvme: freeze IO accesses around format
Date: Wed, 1 Nov 2017 09:21:40 -0700 [thread overview]
Message-ID: <20171101162140.GA29779@infradead.org> (raw)
In-Reply-To: <20171101162147.GA26245@localhost.localdomain>
On Wed, Nov 01, 2017@10:21:47AM -0600, Keith Busch wrote:
>
> Okay, we can freeze single nvme namespace's request queues if desired.
> It's only a little more code to do that.
Not sure we need to bother doing it now, but a comment that we are
lazy might be useful.
> > Also don't we need to also handle this for I/O commands? While
> > non of the currently defined I/O commands would need anything, the
> > spec defines the mechanism? and it might be useful for vendor
> > specific commands
>
> That gets tricky. What if the IO command effects says it needs to run
> exclusively? We don't have a way to quiesce IO queues and then issue our
> exclusive IO through the frozen queue. We'd deadlock trying to allocate
> a request from it.
>
> If it's okay, I'd like to handle the IO command effects separately for
> future work.
True. Maybe we should warn if we have any bit set for I/O commands?
next prev parent reply other threads:[~2017-11-01 16:21 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-27 16:35 [PATCH] nvme: freeze IO accesses around format Jens Axboe
2017-10-27 16:44 ` Keith Busch
2017-10-27 23:07 ` Keith Busch
2017-10-30 14:29 ` Jens Axboe
2017-11-01 15:56 ` Christoph Hellwig
2017-11-01 16:21 ` Keith Busch
2017-11-01 16:21 ` Christoph Hellwig [this message]
2017-10-28 6:45 ` Christoph Hellwig
2017-10-30 14:30 ` Jens Axboe
2017-11-01 15:42 ` Christoph Hellwig
2017-11-01 15:49 ` Keith Busch
2017-11-01 15:43 ` Christoph Hellwig
2017-11-01 15:45 ` Jens Axboe
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