Messages in this thread | | | Date | Thu, 2 Aug 2007 21:48:25 +0200 | From | Ingo Molnar <> | Subject | Re: Scheduling the highest priority task |
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* Martin Roehricht <ml@felicis.org> wrote:
> On 08/02/2007 05:19 PM, Ingo Molnar wrote: > >* Martin Roehricht <ml@felicis.org> wrote: > > > >>That's fine with me, that within the same priority-queue any task can > >>be chosen. But assume two tasks with highly different priorities, such > >>as 105 and 135 are scheduled on the same processor and one of them is > >>now to be migrated -- shouldn't be the queue with task P=105 > >>considered first for migration by this code? Both tasks would use > >>different queues with their own linked lists, right? > > > >yes. What makes you believe that the lower priority one (prio 135) is > >chosen? [ as i said before, that will only be chosen if all tasks in the > >higher-priority queue (prio 105) are either already running on a CPU or > >have recently run so that the cache-hot logic skips them. ] > > This believe is primarily based on my observations of multiple > benchmark runs and also on your statement earlier: »in the SMP > migration code, the 'old scheduler' indeed picks the lowest priority > one«.
oh, sorry, that was meant to be the 'highest priority one' :-/
so i think you got it all right, i just typoed that first sentence.
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