From: Matthew Wilcox <willy@linux.intel.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [REVIEW] NVM Express driver
Date: Fri, 4 Mar 2011 09:46:33 -0500 [thread overview]
Message-ID: <20110304144633.GB3663@linux.intel.com> (raw)
In-Reply-To: <20110304130645.GA21454@infradead.org>
On Fri, Mar 04, 2011 at 08:06:45AM -0500, Christoph Hellwig wrote:
> What's the reason to make this a make_request based driver? That loses
> all the intelligence that has been put into the queueing layer, like I/O
> bandwith controlling and fair scheduling. Is it just queue_lock
> contention? If so it would be great if you could help with testing
> Jens' stack-plug and request allocation scalability patches.
The hardware has the ability to do I/O bandwidth control and fair
scheduling (albeit on a fairly coarse granularity). By doing it in
software, all we're doing for these devices is increasing I/O latency
and burning CPU cycles.
next prev parent reply other threads:[~2011-03-04 14:46 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-03 20:47 [REVIEW] NVM Express driver Matthew Wilcox
2011-03-03 21:13 ` Greg KH
2011-03-03 21:41 ` Matthew Wilcox
2011-03-03 21:51 ` Greg KH
2011-03-03 22:07 ` Matthew Wilcox
2011-03-03 22:22 ` Greg KH
2011-03-04 2:25 ` Andy Lutomirski
2011-03-04 9:02 ` el es
2011-03-04 21:29 ` Greg KH
2011-03-04 12:43 ` Alan Cox
2011-03-04 21:28 ` Greg KH
2011-03-04 21:59 ` Alan Cox
2011-03-04 22:10 ` Greg KH
2011-03-04 22:33 ` Alan Cox
2011-03-04 23:10 ` Greg KH
2011-03-05 10:28 ` Alan Cox
2011-03-04 12:52 ` Mark Brown
2011-03-03 21:33 ` Randy Dunlap
2011-03-04 13:06 ` Christoph Hellwig
2011-03-04 14:46 ` Matthew Wilcox [this message]
2011-03-11 22:29 ` Andi Kleen
2011-03-12 5:51 ` Matthew Wilcox
2011-03-13 17:14 ` Andi Kleen
2011-03-13 17:14 ` Andi Kleen
2011-03-13 18:24 ` Arnd Bergmann
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