Subject: Re: ppc32: Weird process scheduling behaviour with 2.6.24-rc

From: Benjamin Herrenschmidt <[email-masked]>
Date: Sat, 26 Jan 2008 16:15:52 +1100

> > Not that it seems that Michel reported far worse behaviour than what I
> > saw, including pretty hickup'ish X behaviour even without the fair group
> > scheduler compared to 2.6.23. It might be because he's running X niced
> > to -1 (I leave X at 0 and let the scheduler deal with it in general)
> > though.
> 
> Hmm ..with X niced to -1, it should get more cpu power leading to a
> better desktop experience.

It depends as X can end up starving it's own clients, especially with a
compositing manager or other fancy window manager...

> Michel,
> 	You had reported that commit 810e95ccd58d91369191aa4ecc9e6d4a10d8d0c8 
> was the cause for this bad behavior. Do you see behavior change (from good->bad)
> immediately after applying that patch during your bisect process?

Also Michel, double check your .config in both cases.

> I would prefer to have CONFIG_FAIR_GROUP_SCHED +
> CONFIG_FAIR_CGROUP_SCHED on by default. Can you pls let me know how you
> think is the desktop experience with that combination?

I'm going to give that a try but unfortunately, it will have to wait
until I'm back from LCA in a bit more than a week.

Ben.