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

From: Bill Davidsen (davidsen@tmr.com)
Date: Mon Feb 25 2002 - 15:01:04 EST


On Wed, 20 Feb 2002, Paul Jackson wrote:

> I see three levels of synchonization possible here:
>
> 1) As Erich did, use IPI to get immediate application
>
> 2) Wakeup the target task, so that it will "soon" see the
> cpus_allowed change, but don't bother with the IPI, or
>
> 3) Make no effort to expedite notifcation, and let the
> target notice its changed cpus_allowed when (and if)
> it ever happens to be scheduled active again.

(3) looks good, if the process isn't running it makes little difference on
which CPU it doesn't run. Would probably be enough to ensure that if it is
scheduled active the change is noted at that time. "Eventually" is a good
time to do this, when going through schedule code anyway.

-- 
bill davidsen <davidsen@tmr.com>
  CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.

- 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 : Thu Feb 28 2002 - 21:00:17 EST