Re: [PATCH] O6int for interactivity

Davide Libenzi
2003-07-18T13:39:23Z

On Fri, 18 Jul 2003, Mike Galbraith wrote:

> At 03:12 PM 7/16/2003 -0700, Davide Libenzi wrote:
>
> >http://www.xmailserver.org/linux-patches/irman2.c
> >
> >and run it with different -n (number of tasks) and -b (CPU burn ms time).
> >At the same time try to build a kernel for example. Then you will realize
> >that interactivity is not the bigger problem that the scheduler has right
> >now.
>
> I added an irman2 load to contest. Con's changes 06+06.1 stomped it flat
> [1]. irman2 is modified to run for 30s at a time, but with default parameters.

In my case I cannot even estimate the time. It takes 8:33 ususally to do a
bzImage, and after 15 minutes I ctrl-c with only two lines printed in the
console. If you consider the ratio between the total number of lines that
a kernel build spits out, this couls have taken hours. Also, you might
want also to try a low number of processes with a short burn, like the new
patch seems to do to better hit mm players. Something like:

irman2 -n 10 -b 40

Guys, I'm saying this not because I do not appreciate the time Con is
spending on it. I just hate to see time spent in the wrong priorities.
Whatever super privileged sleep->burn pattern you code, it can be
exploited w/out a global throttle for the CPU time assigned to interactive
and non interactive tasks. This is Unix guys and it is used in multi-user
environments, we cannot ship with a flaw like this.

- Davide