Re: Processor sets (pset) for linux kernel 2.5/2.6?

[Antonio Vargas <wind@cocodriloo.com>]

On Sat, Apr 12, 2003 at 12:20:35PM +0100, Shaheed R. Haque wrote:
> 
> Hi,
> 
> Looking through the archive etc., I cannot see any references to pset 
> functionality more recently than
> 
> http://www.ussg.iu.edu/hypermail/linux/kernel/9904.1/0521.html
> 
> announcing an updated patch in April 1999. Are there any plans out there to 
> include this, or similar functionality in 2.5/2.6? I'm particularly interested 
> in getting exclusive access to a CPU (plus or minus HT support, for now anyway).

Shaheed, I think that task->cpu_allowed covers your need, since it
describes a mask of cpu�'s allowed to run the task. CPU migration, for
example, is implemented in current scheduler by saving the
current cpu_allowed, forcing it to contain only the destination CPU and
then restoring it.

I think it's carried over by fork(), but have been unable to find
it on the sources.

HT is accounted as a NUMA SMP system with strong memory affinity
for his 2 cores, so that when running 2 HT processors (2+2 cores),
the tasks are kept preferably on the same HT processor and just bounce
cores, since they share the same cache (don't know exactly L1, L2 or
both, tough).

Greets, Antonio.