From: Jens Axboe <jens.axboe@oracle.com>
To: Shaohua Li <shaohua.li@intel.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC]cfq-iosched: improve hw_tag detection
Date: Tue, 27 Oct 2009 08:45:43 +0100 [thread overview]
Message-ID: <20091027074543.GQ10727@kernel.dk> (raw)
In-Reply-To: <20091027005039.GA14819@sli10-desk.sh.intel.com>
On Tue, Oct 27 2009, Shaohua Li wrote:
> On Mon, Oct 26, 2009 at 07:35:55PM +0800, Jens Axboe wrote:
> > On Mon, Oct 26 2009, Shaohua Li wrote:
> > > If active queue hasn't enough requests and idle window opens, cfq will not
> > > dispatch sufficient requests to hardware. In such situation, current code
> > > will zero hw_tag. But this is because cfq doesn't dispatch enough requests
> > > instead of hardware queue doesn't work. Don't zero hw_tag in such case.
> >
> > Thanks, that looks like a good fix. Curious, is this fixing some
> > regression at your end?
> No, just observed such issue when I play with cfq.
OK thanks, just curious. I will apply it for 2.6.33.
--
Jens Axboe
prev parent reply other threads:[~2009-10-27 7:45 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-26 9:16 [RFC]cfq-iosched: improve hw_tag detection Shaohua Li
2009-10-26 11:35 ` Jens Axboe
2009-10-27 0:50 ` Shaohua Li
2009-10-27 7:45 ` Jens Axboe [this message]
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