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From: Jens Axboe <jaxboe@fusionio.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>,
	Roland Dreier <roland@purestorage.com>,
	Dave Jiang <dave.jiang@intel.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>
Subject: Re: [RFC PATCH 1/2] block: strict rq_affinity
Date: Sat, 23 Jul 2011 20:38:20 +0200	[thread overview]
Message-ID: <4E2B151C.6080900@fusionio.com> (raw)
In-Reply-To: <20110723014633.GA32507@infradead.org>

On 2011-07-23 03:46, Christoph Hellwig wrote:
> On Fri, Jul 22, 2011 at 01:59:39PM -0700, Dan Williams wrote:
>> Some storage controllers benefit from completions always being steered
>> to the strict requester cpu rather than the looser "per-socket" steering
>> that blk_cpu_to_group() attempts by default.
> 
> Isn't this actually dependent on the cpu, and not the storage
> controller?

It is, it's completely indendent of the controller used. Perhaps some
drivers could have a very heavy end io completion handling causing the
problem to become larger, but in general it's an artifact of the CPU and
not the controller.

-- 
Jens Axboe


  reply	other threads:[~2011-07-23 18:38 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-22 20:59 [RFC PATCH 0/2] block: rq_affinity performance fixes Dan Williams
2011-07-22 20:59 ` [RFC PATCH 1/2] block: strict rq_affinity Dan Williams
2011-07-23  1:46   ` Christoph Hellwig
2011-07-23 18:38     ` Jens Axboe [this message]
2011-07-23 18:41   ` Jens Axboe
2011-07-25  1:14     ` Shaohua Li
2011-07-25  8:21       ` Jens Axboe
2011-07-22 20:59 ` [RFC PATCH 2/2] block: adaptive rq_affinity Dan Williams

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