Re: [BUG][2.6.30] Niced processes do not raise CPU frequency with ondemand

From: Frans Pop
Date: Fri Jun 12 2009 - 14:05:32 EST


On Friday 12 June 2009, Pallipadi, Venkatesh wrote:
> On Fri, 2009-06-12 at 10:25 -0700, Frans Pop wrote:
> > On Friday 12 June 2009, Pallipadi, Venkatesh wrote:
> > > What does ignore_nice under cpufreq/ondemand say?
> >
> > Right, that's 1 (was not aware that existed :-P)
> > And changing it to 0 solves the problem.
>
> OK. Good to know that there are no kernel bugs with honoring
> ignore_nice_load setting. :)
>
> > Next question is: how and why does it get set?
> > As userland has not changed (AFAIK), my first suspect remains the
> > kernel.
>
> Kernel never sets this. It is initialized to 0 and provides a /sys
> interface to user. I think it is set by some user app
> (gnome-power-manager or some other app like that). That explains why it
> is 0 initially after boot and gets changed later.
>
> The support for ignore_nice_load=1 was broken in kernel for a short
> while (arounf 2.6.28, IIRC). That may be the reason why this behavior
> was not noticed earlier.

Thanks for the info. I'll see if I can figure out what's responsible.
At least I know where to look now.

Cheers,
FJP
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