Re: [PATCH][RSDL-mm 0/7] RSDL cpu scheduler for 2.6.21-rc3-mm2

From: Ingo Molnar
Date: Tue Mar 13 2007 - 05:39:41 EST



* Mike Galbraith <efault@xxxxxx> wrote:

> I just retested with the encoders at nice 0, and the x/gforce combo is
> terrible. [...]

ok. So nice levels had nothing to do with it - it's some other
regression somewhere. How does the vanilla scheduler cope with the
exactly same workload? I.e. could you describe the 'delta' difference in
behavior - because the delta is what we are interested in mostly, the
'absolute' behavior alone is not sufficient. Something like:

- on scheduler foo, under this workload, the CPU hogs steal 70% CPU
time and the resulting desktop experience is 'choppy': mouse pointer
is laggy and audio skips.

- on scheduler bar, under this workload, the CPU hogs are at 40%
CPU time and the desktop experience is smooth.

things like that - we really need to be able to see the delta.

> [...] Funny thing though, x/gforce isn't as badly affected with a
> kernel build. Any build is quite noticable, but even at -j8, the
> effect doen't seem to be (very brief test warning applies) as bad as
> with only the two encoders running. That seems quite odd.

likewise, how does the RSDL kernel build behavior compare to the vanilla
scheduler's behavior? (what happens in one that doesnt happen in the
other, etc.)

Ingo
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