On Tue, Sep 25, 2007 at 11:13:31AM +0200, Ingo Molnar wrote:
quoted text
> 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
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