From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org,
ctalbott-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org,
rni-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org,
containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Zhao Shuai <zhaoshuai-h+KGxgPPiopAfugRpC6u6w@public.gmane.org>,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.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-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
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
WARNING: multiple messages have this Message-ID (diff)
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
next prev parent reply other threads:[~2012-12-11 14:27 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-10 12:28 performance drop after using blkcg Zhao Shuai
[not found] ` <CAFVn34SxqAJe_4P-WT8MOiG-kmKKD7ge96zoHXQuGqHWPgAt+A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-12-11 7:00 ` Zhao Shuai
2012-12-11 7:00 ` Zhao Shuai
2013-08-29 3:10 ` joeytao
2013-08-29 3:20 ` joeytao
2012-12-11 14:25 ` Vivek Goyal
2012-12-11 14:25 ` Vivek Goyal
2012-12-11 14:25 ` Vivek Goyal
[not found] ` <20121211142518.GA5580-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-12-11 14:27 ` Tejun Heo [this message]
2012-12-11 14:27 ` Tejun Heo
[not found] ` <20121211142742.GE7084-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2012-12-11 14:43 ` Vivek Goyal
2012-12-11 14:43 ` Vivek Goyal
2012-12-11 14:43 ` Vivek Goyal
[not found] ` <20121211144336.GB5580-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-12-11 14:47 ` Tejun Heo
2012-12-11 14:47 ` Tejun Heo
2012-12-11 14:47 ` Tejun Heo
[not found] ` <20121211144718.GF7084-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2012-12-11 15:02 ` Vivek Goyal
2012-12-11 15:02 ` Vivek Goyal
[not found] ` <20121211150234.GC5580-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-12-11 15:14 ` Tejun Heo
2012-12-11 15:14 ` Tejun Heo
2012-12-11 15:14 ` Tejun Heo
[not found] ` <20121211151412.GG7084-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2012-12-11 15:37 ` Vivek Goyal
2012-12-11 15:37 ` Vivek Goyal
2012-12-11 15:37 ` Vivek Goyal
[not found] ` <20121211153725.GD5580-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-12-11 16:01 ` Tejun Heo
2012-12-11 16:01 ` Tejun Heo
2012-12-11 16:01 ` Tejun Heo
[not found] ` <20121211160137.GJ7084-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2012-12-11 16:18 ` Vivek Goyal
2012-12-11 16:18 ` Vivek Goyal
[not found] ` <20121211161820.GE5580-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-12-11 16:27 ` Tejun Heo
2012-12-11 16:27 ` Tejun Heo
2012-12-11 16:27 ` Tejun Heo
2012-12-11 16:18 ` Vivek Goyal
2012-12-11 15:02 ` Vivek Goyal
2012-12-12 7:29 ` Zhao Shuai
2012-12-12 7:29 ` Zhao Shuai
[not found] ` <CAFVn34TqCk71PDgdTAhBo9qTmhD3OwO9RxuyNRXwtkJoYqtOZg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-12-16 4:38 ` Zhu Yanhai
2012-12-16 4:38 ` Zhu Yanhai
2012-12-16 4:38 ` Zhu Yanhai
2012-12-12 7:29 ` Zhao Shuai
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