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From: Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Cc: Jens Axboe <axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>,
	cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH RFC] blkcg: prepare blkcg knobs for default hierarchy
Date: Wed, 23 Apr 2014 14:58:35 -0400	[thread overview]
Message-ID: <20140423185835.GD22755@redhat.com> (raw)
In-Reply-To: <20140423185231.GA4163-9pTldWuhBndy/B6EtB590w@public.gmane.org>

On Wed, Apr 23, 2014 at 02:52:31PM -0400, Tejun Heo wrote:
> Hello,
> 
> On Wed, Apr 23, 2014 at 01:17:20PM -0400, Vivek Goyal wrote:
> > I think we should just require two. One for measuring rate in terms
> > of IOPS and other for measuring rate in terms of [kMG]B/sec.
> 
> I meant between cfq and blk-throttle.  Why do we have separate stats
> for them to present ultimately the same numbers?

Oh, sorry, I had misunderstood your question.

- Number of IOs serviced will be different at throttling layer and
  CFQ layer as throttling accounts IO in terms of bios and CFQ
  accounts in terms of number of requests.

- CFQ might not be operational on a device while throttling might be
  on and one needs bytes stats.

- In a custom kernel throttling might not be on and CFQ is on and
  one needs the stats.

So I think we do require duplication of some stats across throttling
and CFQ, isn't it?

Thanks
Vivek

WARNING: multiple messages have this Message-ID (diff)
From: Vivek Goyal <vgoyal@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>,
	linux-kernel@vger.kernel.org, Li Zefan <lizefan@huawei.com>,
	cgroups@vger.kernel.org
Subject: Re: [PATCH RFC] blkcg: prepare blkcg knobs for default hierarchy
Date: Wed, 23 Apr 2014 14:58:35 -0400	[thread overview]
Message-ID: <20140423185835.GD22755@redhat.com> (raw)
In-Reply-To: <20140423185231.GA4163@mtj.dyndns.org>

On Wed, Apr 23, 2014 at 02:52:31PM -0400, Tejun Heo wrote:
> Hello,
> 
> On Wed, Apr 23, 2014 at 01:17:20PM -0400, Vivek Goyal wrote:
> > I think we should just require two. One for measuring rate in terms
> > of IOPS and other for measuring rate in terms of [kMG]B/sec.
> 
> I meant between cfq and blk-throttle.  Why do we have separate stats
> for them to present ultimately the same numbers?

Oh, sorry, I had misunderstood your question.

- Number of IOs serviced will be different at throttling layer and
  CFQ layer as throttling accounts IO in terms of bios and CFQ
  accounts in terms of number of requests.

- CFQ might not be operational on a device while throttling might be
  on and one needs bytes stats.

- In a custom kernel throttling might not be on and CFQ is on and
  one needs the stats.

So I think we do require duplication of some stats across throttling
and CFQ, isn't it?

Thanks
Vivek

  parent reply	other threads:[~2014-04-23 18:58 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-13  1:32 [PATCH RFC] blkcg: prepare blkcg knobs for default hierarchy Tejun Heo
2014-04-13  1:32 ` Tejun Heo
2014-04-14 18:08 ` Vivek Goyal
2014-04-14 19:32   ` Tejun Heo
     [not found]     ` <20140414193214.GC16835-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2014-04-15 13:53       ` Vivek Goyal
2014-04-15 13:53         ` Vivek Goyal
     [not found]         ` <20140415135359.GA13033-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-04-15 14:06           ` Tejun Heo
2014-04-15 14:06             ` Tejun Heo
2014-04-15 14:18             ` Vivek Goyal
     [not found]               ` <20140415141826.GB17018-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-04-23 17:01                 ` Tejun Heo
2014-04-23 17:01                   ` Tejun Heo
     [not found]                   ` <20140423170141.GJ4781-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2014-04-23 17:17                     ` Vivek Goyal
2014-04-23 17:17                       ` Vivek Goyal
2014-04-23 18:52                       ` Tejun Heo
     [not found]                         ` <20140423185231.GA4163-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2014-04-23 18:58                           ` Vivek Goyal [this message]
2014-04-23 18:58                             ` Vivek Goyal
2014-04-23 19:00                             ` Tejun Heo
     [not found]                               ` <20140423190043.GB4163-9pTldWuhBndy/B6EtB590w@public.gmane.org>
2014-04-23 19:21                                 ` Vivek Goyal
2014-04-23 19:21                                   ` Vivek Goyal
2014-04-23 19:27                                   ` Tejun Heo
2014-05-23 17:39                                   ` Tejun Heo
2014-05-27 12:49                                     ` Vivek Goyal

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