Re: scheduler nice 19 versus 'idle' behavior / static low-priority scheduling

[Nathanael Hoyle <nhoyle@hoyletech.com>]

On Fri, 2009-01-30 at 09:50 +0100, Peter Zijlstra wrote:
> On Fri, 2009-01-30 at 00:49 -0500, Nathanael Hoyle wrote:
> > 
> > 1) Is my problem 'expected' based on others' understanding of the
> > current design of the scheduler, or do I have a one-off problem to
> > troubleshoot here?
> 
> What kernel are you running (or did my eye glance over that detail in
> your longish email) ?
> 

I didn't include it, I should have:

$ uname -a
Linux nightmare 2.6.27-gentoo-r7-nhoyle #2 SMP Wed Jan 28 19:04:37 EST
2009 x86_64 Intel(R) Core(TM)2 Quad CPU Q9450 @ 2.66GHz GenuineIntel
GNU/Linux

> > 2) Am I overlooking obvious alternative (but clean) fixes?
> 
> Maybe, we fixed a glaring bug in this department recently (or more even,
> if you're on older than .28).
> 

Yep, .27 atm.

> > 3) Does anyone else see the need for static, but low process priorities?
> 
> Yep, its rather common.
> 
> > 4) What is the view of introducing a new scheduler class to handle this?
> 
> We should have plenty available, SCHED_IDLE should just work -- as
> should nice 19 for that matter.
> 

Thanks!
-Nathanael