Re: [ckrm-tech] Re: [Lse-tech] [PATCH] cpusets - big numa cpu and memory placement

Paul Jackson
2004-10-07T09:02:36Z

Matthew wrote:
> > Perhaps these flags should be called:
> > mems_exclusive_precursor
> > cpus_exclusive_precursor
> > ;).
>
> Ok... So if we could offer the 'real' exclusion that the PBS and LSF
> workload managers offer directly, would that suffice? Meaning, could we
> make PBS and LSF work on top of in-kernel mechanisms that offer 'real'
> exclusion. 'Real' exclusion defined as isolated groups of CPUs and
> memory that the kernel can guarantee will not run other processes? That
> way we can get the job done without having to rely on these external
> workload managers, and be able to offer this dynamic partitioning to all
> users. Thoughts?

I agree entirely. Before when I was being a penny pincher about
how much went in the kernel, it might have made sense to have
the mems_exclusive and cpus_exclusive precursor flags.

But now that we have demonstrated a bone fide need for a really
really exclusive cpuset, it was silly of me to consider offering:

> > mems_exclusive_precursor
> > cpus_exclusive_precursor
> > really_really_exclusive

These multiple flavors just confuse and annoy.

You're right. Just one flag option, for the really exclusive cpuset,
is required here.

A different scheduler domain (whether same scheduler with awareness of
the boundaries, or something more substantially distinct) may only be
attached to a cpuset if it is exclusive.

--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <pj@sgi.com> 1.650.933.1373