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

Hubertus Franke
2004-10-02T18:19:14Z

Paul Jackson wrote:
> Hubertus wrote:
>
>>Marc, cpusets lead to physical isolation.
>
>
> This is slightly too terse for my dense brain to grok.
> Could you elaborate just a little, Hubertus? Thanks.
>

A minimal quote from your website :-)

"CpuMemSets provides a new Linux kernel facility that enables system
services and applications to specify on which CPUs they may be
scheduled, and from which nodes they may allocate memory."

Since I have addressed the cpu section it seems obvious that
in order to ISOLATE different workloads, you associate them onto
non-overlapping cpusets, thus technically they are physically isolated
from each other on said chosen CPUs.

Given that cpuset hierarchies translate into cpu-affinity masks,
this desired isolation can result in lost cycles globally.

I believe this to be orthogonal to share settings. To me both
are extremely desirable features.

I also pointed out that if you separate mechanism from API, it
is possible to move the CPU set API under the CKRM framework.
I have not thought about the memory aspect.

-- Hubertus