Messages in this thread | | | Date | Fri, 07 Nov 2014 10:35:00 +0100 | From | Daniel Lezcano <> | Subject | Re: [PATCH V2 1/5] sched: idle: cpuidle: Check the latency req before idle |
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On 11/07/2014 05:29 AM, Preeti U Murthy wrote: > On 11/06/2014 07:12 PM, Daniel Lezcano wrote: >> >> Preeti, >> >> I am wondering if we aren't going to a false debate. >> >> If the latency_req is 0, we should just poll and not enter in any idle >> state even if one has zero exit latency. With a zero latency req, we >> want full reactivity on the system, not enter an idle state with all the >> computation in the menu governor, no ? >> >> I agree this patch changes the behavior on PowerPC, but only if the >> latency_req is set to zero. I don't think we are worried about power >> saving when setting this value. >> >> Couldn't the patch accepted as it is for the sake of consistency on all >> the platform and then we optimize cleanly for the special latency zero >> case ? > > Alright Daniel, you can go ahead. I was thinking this patch through and > now realize that, like you point out the logic will only get complicated > with all the additional hack. > > But would it be possible to add the weak arch_cpu_idle_loop() call for > the cases where latency requirement is 0 like you had suggested earlier > ? This would ensure the polling logic does not break on PowerPC and we > don't bother the governor even. I will add the function in the core > PowerPC code. If arch does not define this function it will fall back to > cpu_idle_loop(). Fair enough?
Yes, sounds good.
I will add the weak function as the first patch in the series.
Thanks for your reviews.
-- Daniel
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