ULE/yielding patch for testing.

[Nick Evans]

On Tue, 2 Oct 2007 16:53:33 -0700 (PDT)
Jeff Roberson <jroberson at chesapeake.net> wrote:

> Enclosed is a patch that does two things:
> 
> 1)  Reduces UP context switch time by over 10% making it faster than 4BSD 
> on UP.  On SMP it's hard to compare since ULE can do as many as 30x as 
> many switches per second on my 8way system.
> 
> 2)  Restores old sched_yield() behavior from 6.x.  This was changed in 
> -current unintentionally I think.
> 
> I'd appreciate any extra testing.  The ULE context switch time 
> improvements required some changes to the frequency that we recalculate 
> priorities.  I'm mostly interested in hearing whether this causes any 
> regression in normal workloads.
> 
> Those of you still using 4BSD can also verify that the yield changes don't 
> cause any problems there.
> 
> Thanks,
> Jeff

Jeff,

I haven't noticed any adverse affects with this patch on yesterdays
CURRENT+ULE. System is a Pentium D 915 with 1 gig ram. Built a bunch of larger
ports while browsing in firefox and setting up enlightenment-devel,
interactivity was good. Enlightenment's eye-candy stayed very fluid.

Nick