Re: SCHED: Is task migration necessary in sched_exec().

From: Rakib Mullick
Date: Wed Dec 23 2009 - 05:47:01 EST


On 12/23/09, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Wed, 2009-12-23 at 16:14 +0600, Rakib Mullick wrote:
>
>
> Well, if there's an imbalance the 'slow' load-balancer will move it
> around eventually anyway, and since it will then have build up a larger
> cache footprint it will be even more expensive.
>
If there is an imbalance - then the overloaded task will moved. Why the
_current_ task? It is getting the CPU that it was waiting for. We need to
move overloaded task, not a task which is about to get execute. At this
perticular moment pushing it away doesn't make sense, isn't it?

> So moving it when its cheapest is the best all-round trade-off, isn't
> it?

I don't have any argue with cache footprint issue.
>
>
thanks,
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