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From: Tejun Heo <tj@kernel.org>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: Zhao Shuai <zhaoshuai@freebsd.org>,
	axboe@kernel.dk, ctalbott@google.com, rni@google.com,
	linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
	containers@lists.linux-foundation.org
Subject: Re: performance drop after using blkcg
Date: Tue, 11 Dec 2012 06:27:42 -0800	[thread overview]
Message-ID: <20121211142742.GE7084@htj.dyndns.org> (raw)
In-Reply-To: <20121211142518.GA5580@redhat.com>

On Tue, Dec 11, 2012 at 09:25:18AM -0500, Vivek Goyal wrote:
> In general, do not use blkcg on faster storage. In current form it
> is at best suitable for single rotational SATA/SAS disk. I have not
> been able to figure out how to provide fairness without group idling.

I think cfq is just the wrong approach for faster non-rotational
devices.  We should be allocating iops instead of time slices.

Thanks.

-- 
tejun

  reply	other threads:[~2012-12-11 14:27 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CAFVn34SxqAJe_4P-WT8MOiG-kmKKD7ge96zoHXQuGqHWPgAt+A@mail.gmail.com>
2012-12-11  7:00 ` performance drop after using blkcg Zhao Shuai
2013-08-29  3:10   ` joeytao
2013-08-29  3:20   ` joeytao
2012-12-11 14:25 ` Vivek Goyal
2012-12-11 14:27   ` Tejun Heo [this message]
2012-12-11 14:43     ` Vivek Goyal
2012-12-11 14:47       ` Tejun Heo
2012-12-11 15:02         ` Vivek Goyal
2012-12-11 15:14           ` Tejun Heo
2012-12-11 15:37             ` Vivek Goyal
2012-12-11 16:01               ` Tejun Heo
2012-12-11 16:18                 ` Vivek Goyal
2012-12-11 16:27                   ` Tejun Heo
2012-12-12  7:29   ` Zhao Shuai
2012-12-16  4:38     ` Zhu Yanhai

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