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From: Tejun Heo <tj@kernel.org>
To: Vivek Goyal <vgoyal@redhat.com>
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 15:27:07 -0400	[thread overview]
Message-ID: <20140423192707.GD4163@mtj.dyndns.org> (raw)
In-Reply-To: <20140423192108.GF22755@redhat.com>

Hello,

On Wed, Apr 23, 2014 at 03:21:09PM -0400, Vivek Goyal wrote:
> In general this idea makes sense. Exporting both request and bio will
> solve the problem of io accounting. Also that should allow us to
> get rid of blkio.io_merged.

Yeah, that'd make more sense, I think.  IO submitted vs. actually
executed after merging.  Pretty clear definition.

> What about sync/async differentiation? Throttling layer seems to flag a request sync
> only if bio->bi_rw flag has REQ_SYNC set. While CFQ seems to consider
> request sync if bio is either read or bio->bi_rw has REQ_SYNC flag set.

Heh, I think we'd need to unify those no matter what.  The subtle
difference is extremely confusing.

> So we need to make this definition uniform. Or I am wondering do we
> really need to export sync/async data. (Again put in by google folks).
> How useful this info really is. 

Hmmmm... yeah, maybe that'd be the best way to go about it.

Thanks.

-- 
tejun

  reply	other threads:[~2014-04-23 19:27 UTC|newest]

Thread overview: 15+ 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
2014-04-14 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
     [not found]         ` <20140415135359.GA13033-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
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
     [not found]                   ` <20140423170141.GJ4781-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
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
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 19:27                                   ` Tejun Heo [this message]
2014-05-23 17:39                                   ` Tejun Heo
2014-05-27 12:49                                     ` Vivek Goyal

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