On Wednesday 27 October 2010 01:43:25 Thomas Renninger wrote: > cpu_idle events (transition into sleep state and exiting) are > both fired in pm_idle(). > > Entering sleep state and exiting should always get fired inside > pm_idle() already. > > This is a revert of commit c882e0feb937af4e5b991cbd1c Robert: I expect you tested this on a machine with no cpuidle driver registered? I should have had a deeper look at this at once, done so now: Current cpu_idle, power_start/end (same before my changes) behavior on X86 is rather weird (without this patch): if pm_idle is: poll_idle -> should throw double end events default_idle -> only throws power_start, your patch fixed that, but in the generic cpu_idle thread function which always gets executed also if pm_idle != default_idle So Robert fixed this case, but at the wrong place. cpuidle_idle_call -> depends whether intel_idle or acpi_idle driver registered: intel_idle -> throws a cpu idle state event, still double end events (one from cpuidle, one from process_{32,64}.c, due to Robert's patch acpi_idle -> whether a power_start event is thrown at all depends on (cmp with acpi_idle_do_entry()): cx->entry_method == ACPI_CSTATE_FFH will end up in a power_start event via: acpi_processor_ffh_cstate_enter(cx) mwait_idle_with_hints() but it will not in case of: cx->entry_method == ACPI_CSTATE_HALT or IO based switching (the else path there): /* IO port based C-state */ Again without this(my) patch you get: poll_idle -> double end events default_idle -> all is fine (with your patch) cpuidle_idle_call intel_idle registered -> double end events acpi_idle registered -> double end events start events may not be thrown at all. perf timechart can handle double end events, this may be the reason this was overseen. Argh, I tried to come up with patches, but run out of time. I will send something soon. I also found a bug in my userspace stuff: I forgot to convert u64 to u32..., sorry about that. I try to resend everything tomorrow. Thomas -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html