Re: interactive task starvation

Willy Tarreau
2006-03-21T17:50:43Z

On Wed, Mar 22, 2006 at 02:20:10AM +1100, Con Kolivas wrote:
> On Wednesday 22 March 2006 01:17, Con Kolivas wrote:
> > I actually believe the same effect can be had by a tiny
> > modification to enable/disable the estimator anyway.
>
> Just for argument's sake it would look something like this.
>
> Cheers,
> Con
> ---
> Add sysctl to enable/disable cpu scheduer interactivity estimator

At least, in May 2005, the equivalent of this patch I tested on
2.6.11.7 considerably improved responsiveness, but there was still
this very annoying slowdown when the load increased. vmstat delays
increased by one second every 10 processes. I retried again around
2.6.14 a few months ago, and it was the same. Perhaps Mike's code
and other changes in 2.6-mm really fix the initial problem (array
switching ?) and then only the interactivity boost is causing the
remaining trouble ?

Cheers,
Willy