Messages in this thread | | | Subject | Re: CFS scheduler unfairly prefers pinned tasks | From | Mike Galbraith <> | Date | Tue, 06 Oct 2015 14:17:18 +0200 |
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On Tue, 2015-10-06 at 21:06 +1100, paul.szabo@sydney.edu.au wrote:
> And further... the CFS is meant to be fair, using things like vruntime > to preempt, and throttling. Why are those pinned tasks not preempted or > throttled?
Imagine you own a 8192 CPU box for a moment, all CPUs having one pinned task, plus one extra unpinned task, and ponder what would have to happen in order to meet your utilization expectation. <time passes> Right.
What you're seeing is not a bug. No task can occupy more than one CPU at a time, making space reservation on multiple CPUs a very bad idea.
-Mike
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