Re: [PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-27 Thread Rafael J. Wysocki
On Wednesday, November 14, 2012 05:56:30 PM Julius Werner wrote: > Many cpuidle drivers measure their time spent in an idle state by > reading the wallclock time before and after idling and calculating the > difference. This leads to erroneous results when the wallclock time gets > updated by anoth

Re: [PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-26 Thread Len Brown
>> drivers/idle/intel_idle.c | 14 +- Acked-by: Len Brown thanks! -Len ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev

Re: [PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-26 Thread Len Brown
On 11/15/2012 04:04 AM, Preeti Murthy wrote: > Hi all, > > The code looks correct and inviting to me as it has led to good cleanups. > I dont think passing 0 as the argument to the function > sched_clock_idle_wakeup_event() > should lead to problems,as it does not do anything useful with the > pas

Re: [PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-20 Thread Rafael J. Wysocki
On Wednesday, November 14, 2012 05:56:30 PM Julius Werner wrote: > Many cpuidle drivers measure their time spent in an idle state by > reading the wallclock time before and after idling and calculating the > difference. This leads to erroneous results when the wallclock time gets > updated by anoth

Re: [PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-15 Thread Daniel Lezcano
On 11/15/2012 02:56 AM, Julius Werner wrote: > Many cpuidle drivers measure their time spent in an idle state by > reading the wallclock time before and after idling and calculating the > difference. This leads to erroneous results when the wallclock time gets > updated by another processor in the

Re: [PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-15 Thread Preeti Murthy
Hi all, The code looks correct and inviting to me as it has led to good cleanups. I dont think passing 0 as the argument to the function sched_clock_idle_wakeup_event() should lead to problems,as it does not do anything useful with the passed arguments. My only curiosity is what was the purpose o

[PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-14 Thread Julius Werner
Many cpuidle drivers measure their time spent in an idle state by reading the wallclock time before and after idling and calculating the difference. This leads to erroneous results when the wallclock time gets updated by another processor in the meantime, adding that clock adjustment to the idle st

Re: [PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-14 Thread Julius Werner
> Maybe you can remove all these computations and set the flag > en_core_tk_irqen for the driver ? That will be handled by the cpuidle > framework, no ? > > Same comment for the intel_idle driver. Yeah, I thought about that, too. I was a little too afraid of touching the sched_clock_idle_wakeup_ev

Re: [PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-14 Thread Daniel Lezcano
On 11/13/2012 10:52 PM, Julius Werner wrote: > Many cpuidle drivers measure their time spent in an idle state by > reading the wallclock time before and after idling and calculating the > difference. This leads to erroneous results when the wallclock time gets > updated by another processor in the

Re: [PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-14 Thread Daniel Lezcano
On 11/14/2012 10:06 AM, Deepthi Dharwar wrote: > On 11/14/2012 03:22 AM, Julius Werner wrote: >> Many cpuidle drivers measure their time spent in an idle state by >> reading the wallclock time before and after idling and calculating the >> difference. This leads to erroneous results when the wallcl

Re: [PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-14 Thread Deepthi Dharwar
On 11/14/2012 03:22 AM, Julius Werner wrote: > Many cpuidle drivers measure their time spent in an idle state by > reading the wallclock time before and after idling and calculating the > difference. This leads to erroneous results when the wallclock time gets > updated by another processor in the

[PATCH] cpuidle: Measure idle state durations with monotonic clock

2012-11-13 Thread Julius Werner
Many cpuidle drivers measure their time spent in an idle state by reading the wallclock time before and after idling and calculating the difference. This leads to erroneous results when the wallclock time gets updated by another processor in the meantime, adding that clock adjustment to the idle st