Re: [patch/backport] CFS scheduler, -v22, for v2.6.23-rc8, v2.6.22.8, v2.6.21.7, v2.6.20.20

[Ingo Molnar <mingo@elte.hu>]

* Matthew <jackdachef@gmail.com> wrote:

> Thanks for your answer (sorry, I didn't know your email had changed)
> 
> well, this will take some time since I don't work every day & it's 
> turned off most of the time, hope that is OK
> 
> before I proceed with that data-collection:
> 
> do you think it is possible that it might be related to "Fair group 
> CPU scheduler" being selected ?

i think if you are relatively sure that the box does not have any real 
3D hardware in it (supported by X) then glxgears will interact badly 
with X and can cause such symptoms. In that case glxgears 'spams' the X 
server with requests and everyone else suffers from that. The fair-group 
scheduler indeed could shift CPU usage of X just enough (in X's favor!) 
that might trigger such problems. Such "spam X" workloads often react in 
a paradoxial way: a scheduler that gives X _more_ CPU time will appear 
to be "less interactive".)

	Ingo