Messages in this thread | | | Date | Thu, 26 Sep 2013 10:28:27 +0200 | From | Daniel Lezcano <> | Subject | Re: [PATCH 18/21] cpuidle: don't call poll_idle_init() for every cpu |
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On 09/26/2013 08:09 AM, Viresh Kumar wrote: > On 26 September 2013 03:52, Daniel Lezcano <daniel.lezcano@linaro.org> wrote: >> On 09/22/2013 03:21 AM, Viresh Kumar wrote: >>> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > > This deserved a log, sorry for missing that :( > >> The optimization sounds good but IMHO if we can move this state out of >> the cpuidle common framework that would be nicer. >> >> The poll_idle is only applicable for x86 (acpi_driver and intel_idle), >> hence I suggest we move this state to these drivers, that will cleanup >> the framework code and will remove index shift macro >> CPUIDLE_DRIVER_STATE_START which IMHO is weid and prone-to-error. > > Lets see what X86 folks have to say about it and then we can do it.. > Btw, wouldn't that add some code duplication in those two drivers?
Yes, certainly and that will impact also the menu select governor function:
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/* * We want to default to C1 (hlt), not to busy polling * unless the timer is happening really really soon. */ if (data->expected_us > 5 && !drv->states[CPUIDLE_DRIVER_STATE_START].disabled && dev->states_usage[CPUIDLE_DRIVER_STATE_START].disable == 0) data->last_state_idx = CPUIDLE_DRIVER_STATE_START;
/* * Find the idle state with the lowest power while satisfying * our constraints. */ for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) { struct cpuidle_state *s = &drv->states[i]; struct cpuidle_state_usage *su = &dev->states_usage[i];
if (s->disabled || su->disable) continue; if (s->target_residency > data->predicted_us) continue; if (s->exit_latency > latency_req) continue; if (s->exit_latency * multiplier > data->predicted_us) continue;
data->last_state_idx = i; data->exit_us = s->exit_latency; }
....
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