[dm-devel] Re: IO scheduler based IO controller V10

[Mike Galbraith]

On Fri, 2009-10-02 at 11:40 -0400, Vivek Goyal wrote:
> On Fri, Oct 02, 2009 at 05:32:00PM +0200, Mike Galbraith wrote:
> > On Fri, 2009-10-02 at 17:27 +0200, Corrado Zoccolo wrote:
> > > On Fri, Oct 2, 2009 at 2:49 PM, Vivek Goyal <vgoyal at redhat.com> wrote:
> > > > On Fri, Oct 02, 2009 at 12:55:25PM +0200, Corrado Zoccolo wrote:
> > > >
> > > > Actually I am not touching this code. Looking at the V10, I have not
> > > > changed anything here in idling code.
> > > 
> > > I based my analisys on the original patch:
> > > http://lkml.indiana.edu/hypermail/linux/kernel/0907.1/01793.html
> > > 
> > > Mike, can you confirm which version of the fairness patch did you use
> > > in your tests?
> > 
> > That would be this one-liner.
> > 
> 
> Ok. Thanks. Sorry, I got confused and thought that you are using "io
> controller patches" with fairness=1.
> 
> In that case, Corrado's suggestion of refining it further and disabling idling
> for seeky process only on non-rotational media (SSD and hardware RAID), makes
> sense to me.

One thing that might help with that is to have new tasks start out life
meeting the seeky criteria.  If there's anything going on, they will be.

	-Mike