lkml.org 
[lkml]   [2009]   [May]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: IO scheduler based IO Controller V2
From
Hi Vivek,

From: Vivek Goyal <vgoyal@redhat.com>
Subject: Re: IO scheduler based IO Controller V2
Date: Wed, 6 May 2009 21:25:59 -0400

> On Thu, May 07, 2009 at 09:18:58AM +0900, Ryo Tsuruta wrote:
> > Hi Vivek,
> >
> > > Ryo, dm-ioband breaks the notion of classes and priority of CFQ because
> > > of FIFO dispatch of buffered bios. Apart from that it tries to provide
> > > fairness in terms of actual IO done and that would mean a seeky workload
> > > will can use disk for much longer to get equivalent IO done and slow down
> > > other applications. Implementing IO controller at IO scheduler level gives
> > > us tigher control. Will it not meet your requirements? If you got specific
> > > concerns with IO scheduler based contol patches, please highlight these and
> > > we will see how these can be addressed.
> >
> > I'd like to avoid making complicated existing IO schedulers and other
> > kernel codes and to give a choice to users whether or not to use it.
> > I know that you chose an approach that using compile time options to
> > get the same behavior as old system, but device-mapper drivers can be
> > added, removed and replaced while system is running.
> >
>
> Same is possible with IO scheduler based controller. If you don't want
> cgroup stuff, don't create those. By default everything will be in root
> group and you will get the old behavior.
>
> If you want io controller stuff, just create the cgroup, assign weight
> and move task there. So what more choices do you want which are missing
> here?

What I mean to say is that device-mapper drivers can be completely
removed from the kernel if not used.

I know that dm-ioband has some issues which can be addressed by your
IO controller, but I'm not sure your controller works well. So I would
like to see some benchmark results of your IO controller.

Thanks,
Ryo Tsuruta


\
 
 \ /
  Last update: 2009-05-11 13:25    [W:0.157 / U:0.440 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site