Re: [Lse-tech] Node affine NUMA scheduler extension

Martin J. Bligh (mbligh@aracnet.com)
Tue, 27 May 2003 08:38:52 -0700


> Interesting observation, I didn't make it when I tried the lazy
> homenode (quite a while ago). But I was focusing on MPI jobs. So what
> if we add a condition to CAN_MIGRATE which disables the cache affinity
> before the first load balance?
>
>> Migration directly on fork/clone requires a lot
>> of changes and also breaks down on some benchmarks.
>
> Hmmm, I wouldn't allow this to any task/child, only to special
> ones. Under 2.4 I currently use a sched_balance_fork() function
> similar to sched_balance_exec(). Tasks have a default initial load
> balancing policy of being migrated (and selecting the homenode) at
> exec(). This can be changed (with prctl) to fork(). The ilb policy is
> inheritable. Works fine for OpenMP jobs.

It'd be nice not to require user intervention here ... is it OK to
set CAN_MIGRATE for all clone operations?

M.

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