Re: Scheduling the highest priority task

From: Ingo Molnar
Date: Thu Aug 02 2007 - 11:19:36 EST



* Martin Roehricht <ml@xxxxxxxxxxx> 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. ]

Ingo
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