Messages in this thread | | | Date | Fri, 8 Nov 2019 21:46:42 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 4/7] sched: Optimize pick_next_task() |
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On Fri, Nov 08, 2019 at 02:33:48PM +0000, Quentin Perret wrote: > On Friday 08 Nov 2019 at 14:15:57 (+0100), Peter Zijlstra wrote:
> > Also remove the unlikely() from the idle case, it is in fact /the/ way > > we select idle -- and that is a very common thing to do. > > I assumed this was to optimize the case where we did find a cfs task to > run. That is, we can afford to hit the unlikely case when there is no > work to do after, but when there is, we shouldn't spend time checking > the idle case. Makes sense ?
There is that, but it is also the way we pick idle when nr_running drops to 0.
I just couldn't make up my mind if the unlikely made sense or not.
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