linux-kernel - Re: [RFC] writeback and cgroup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20120422142648.GA9530@localhost>
Date:	Sun, 22 Apr 2012 22:26:48 +0800
From:	Fengguang Wu <fengguang.wu@...el.com>
To:	Tejun Heo <tj@...nel.org>
Cc:	Vivek Goyal <vgoyal@...hat.com>, Jan Kara <jack@...e.cz>,
	Jens Axboe <axboe@...nel.dk>, linux-mm@...ck.org,
	sjayaraman@...e.com, andrea@...terlinux.com, jmoyer@...hat.com,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
	kamezawa.hiroyu@...fujitsu.com, lizefan@...wei.com,
	containers@...ts.linux-foundation.org, cgroups@...r.kernel.org,
	ctalbott@...gle.com, rni@...gle.com, lsf@...ts.linux-foundation.org
Subject: Re: [RFC] writeback and cgroup

On Fri, Apr 20, 2012 at 02:33:01PM -0700, Tejun Heo wrote:
> On Fri, Apr 20, 2012 at 03:29:30PM -0400, Vivek Goyal wrote:
> > I am personally is not too excited about the case of putting async IO
> > in separate groups due to the reason that async IO of one group will
> > start impacting latencies of sync IO of another group and in practice
> > it might not be desirable. But there are others who have use cases for
> > separate async IO queue. So as long as switch is there to change the
> > behavior, I am not too worried.
> 
> Why not just fix cfq so that it prefers groups w/ sync IOs?

There may be a sync+async group in front, but when switch into it, it
decides to give its async queue a run. That's not necessarily a bad
decision, but we do lose some control here.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/