Re: [git] CFS-devel, latest code

Srivatsa Vaddagiri
2007-09-25T09:34:29Z

On Tue, Sep 25, 2007 at 11:13:31AM +0200, Ingo Molnar wrote:
> ok, i'm too seeing some sort of latency weirdness with
> CONFIG_FAIR_GROUP_SCHED enabled, _if_ there's Xorg involved which runs
> under root uid on my box - and hence gets 50% of all CPU time.
>
> Srivatsa, any ideas? It could either be an accounting buglet (less
> likely, seems like the group scheduling bits stick to the 50% splitup
> nicely), or a preemption buglet. One potential preemption buglet would
> be for the group scheduler to not properly preempt a running task when a
> task from another uid is woken?

Yep, I noticed that too.

check_preempt_wakeup()
{
...

if (is_same_group(curr, p)) {
^^^^^^^^^^^^^

resched_task();
}

}

Will try a fix to check for preemption at higher levels ..

--
Regards,
vatsa