Re: SCHED_ULE on desktop system

On Mon, Oct 01, 2007 at 11:30:16AM -0700, Jeff Roberson wrote:
> >I have the same problems as Roman: once I compile something, most of X
> >applications become slow as hell with lagging screen refresh.  That's on
> >-CURRENT (with all debug, malloc, invariant things disabled) with ULE
> >and Xorg 4.3 (I'll test with the legacy scheduler as soon as possible).
> >This behavior does not occur on 6.2 but with Xorg 7.2, so I really suspect
> >last Xorg release to be guilty.  Jeff you often mentioned tests on your
> >laptop, could you check what Xorg version your run?
> 
> xorg-7.2            X.Org complete distribution metaport
> xorg-server-1.2.0_2,1 X.Org X server and related programs
> 
> If you're running very recent current you can try renicing X negatively. 
> If you nice -20 and it doesn't improve then it's probably not the cpu 
> scheduler causing the delay.  What display driver are you using?  How much 
> cpu is X using while you're experiencing the lag?
>

I tried with _4BSD and it gives the same behavior (I even downgraded
Xorg to 7.2).  Renicing X does not really help.

I use nvidia or nv driver (nvidia one is a bit less worse).  The lag can
even appears with 4% of CPU usage according to top(1).
Thanks to your remarks and my tests, I'm now sure it's scheduler
independent.  It seems 7-CURRENT is slower than 6.X regarding I/O :(
For info the box is a 1.2GHz Athlon with 1GB of RAM and swap is never
used.

-- 
Marc