Messages in this thread | | | Date | Thu, 9 Mar 2023 13:44:13 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 10/10] sched/fair: Implement an EEVDF like policy |
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On Thu, Mar 09, 2023 at 10:06:33AM +0100, Peter Zijlstra wrote: > Hi Mike! > > On Wed, Mar 08, 2023 at 02:36:01PM +0100, Mike Galbraith wrote: > > On Wed, 2023-03-08 at 09:39 +0100, Mike Galbraith wrote: > > > > > > Curiosity got the best of me... > > > > Remember this little bugger, allegedly distilled from a real > > application control thread starvation issue? > > Oooh, yeah, I should still have that somewhere. I'll try and remember > what exactly was needed to make it behave properly.
That thing wants both wakeup preemption and sleeper bonus. Specifically, it needs the signal to insta-preempt the 'pointless' kill loop.
What happens is that while positive lag, we get this, when negative lag happens wakeup-preemption is not achieved and we get delayed by a full tick.
This gets us very little actual runtime.
Let me see what do do about that...
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