Re: [Lse-tech] Re: [PATCH] O(1) scheduler set_cpus_allowed for non-current tasks

From: Kimio Suganuma (k-suganuma@mvj.biglobe.ne.jp)
Date: Wed Feb 20 2002 - 20:40:56 EST


Hi all,

On Wed, 20 Feb 2002 17:12:21 -0800
Paul Jackson <pj@engr.sgi.com> wrote:

> > Another problem is the right moment to change the cpu field of the
> > task. ... The IPI to the target CPU is the same as in the
> > initial design of Ingo. It has to wait for the task to unschedule and
> > knows it will find it dequeued.
>
> How about not changing anything of the target task synchronously,
> except for some new "proposed_cpus_allowed" field. Set that
> field and get out of there. Let the target process run the
> set_cpus_allowed() routine on itself, next time it passes through
> the schedule() code. Leave it the case that the set_cpus_allowed()
> routine can only be run on the current process.
>
> Perhaps others need this cpus_allowed change (and the migration
> of a task to a different allowed cpu) to happen "right away".
> But I don't, and I don't (yet) know that anyone else does.

CPU hotplug needs to change cpus_allowed in definite time.
When a process is sleeping for 100000 seconds, how can we offline
a CPU the process belongs?

Regards,
Kimi

-- 
Kimio Suganuma <k-suganuma@mvj.biglobe.ne.jp>

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sat Feb 23 2002 - 21:00:29 EST