Messages in this thread | | | Date | Tue, 7 Jan 2014 14:25:44 +0530 | Subject | Re: [LNG] Re: [Query] Ticks happen in pair for NO_HZ_FULL cores ? | From | Viresh Kumar <> |
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On 7 January 2014 14:17, Peter Zijlstra <peterz@infradead.org> wrote: > On Mon, Dec 23, 2013 at 01:48:02PM +0530, Viresh Kumar wrote: >> *But wouldn't it make sense if we can tell scheduler that don't queue >> these works on a CPU that is running in NO_HZ_FULL mode?* > > No,.. that's the wrong way around.
Hmm.. Just to make it clear I didn't meant that any input from workqueue code should go to scheduler but something like this:
Scheduler will check following before pushing a task on any CPU: - If that CPU is part of NO_HZ_FULL cpu list? - If yes, is that CPU running only one task for now? i.e. running task for best performance case? - If yes, then don't queue new task to that CPU, whether task belongs to workqueue or not doesn't matter.
> That looks to be a normal unpinned timer, it should migrate to a 'busy' > cpu once the one its running on it going idle. > > ISTR people trying to make that active and also migrating on nohz full > or somesuch, just like the workqueues. Forgot what happened with that; > if it got dropped it should probably be ressurected.
I will search for that in archives..
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