On Tuesday 21 June 2011 09:59 PM, deepthi wrote: > On Tuesday 21 June 2011 03:12 AM, Benjamin Herrenschmidt wrote: >> On Mon, 2011-06-20 at 22:48 +0530, deepthi wrote: >>> On Friday 17 June 2011 09:54 AM, Benjamin Herrenschmidt wrote: >>>> On Wed, 2011-06-01 at 18:05 +0530, Deepthi Dharwar wrote: >>>>> Hi, >>>>> >>>>> Please find below a patch, which has perf_events added for pseries (ppc64) >>>>> platform in order to emit the trace required for perf timechart. >>>>> It essentially enables perf timechart for pseries platfrom to analyse >>>>> power savings events like cpuidle states. >>>> >>>> Unless I'm mistaken, you added traces to dedicated CPU idle sleep but >>>> not shared processor. Any reason ? >>>> >>> Yes, the traces were added only to dedicated CPU idle sleep and not for >>> shared processor. This was added only for RFC purpose, and looking for >>> comments from trace implementation point of view. This can be >>> easily extended to the latter too. >> >> Please do both. >> > Yes, I ll do so. > >>>> Also I don't really know that tracing stuff but what's the point of >>>> having start/end _and trace_cpu_idle if you're going to always start & >>>> end around a single occurence of trace_cpu_idle ? >>>> >>> power_start/end are the APIs that were used initially >>> and they are going to be deprecated in the upcoming kernel releases. >>> trace_cpu_idle call is going to replace power start/end routines. >>> To maintain backward compatibility and uniformity, both the routines >>> have been used. >>> (ref:https://lkml.org/lkml/2010/11/14/60ref:https://lkml.org/lkml/2010/11/14/60) >> >> Backward compatible with what ? Userspace ? Do we care in that specific >> case since it's a new feature ? >> > Going forward, we can just have trace_cpu_idle call and > remove the power_start/end calls. > >>>> Wouldn't there be a way to start/end and then trace the snooze and >>>> subsequent cede within the same start/end section or that makes no >>>> sense ? >>>> >>> We wanted to find the residency time of both Snooze as well as cede >>> separately. Knowing this will help us tweak our cpuidle code. So, both >>> have been captured separately. >>> >>>> Also would there be any interest in doing the tracing more generically >>>> in idle.c ? >>>> >>> Yes, this tracing is already implemented for Intel platform. This would >>> be a part of cpuidle framework. Going further, once the power cpuidle >>> framework is ported and ready, we will extend this trace there as well. >>> (ref:https://lkml.org/lkml/2011/6/7/375) >> >> So do we need to apply this patch at all since the cpuidle stuff is >> happening too ? >> > > Well, not really. This is more for RFC purpose. > I just wanted to share this patch, as we are using it to evaluate > cpu idle on ppc64. > I will re-base the patch and move it to the cpu idle for power framework. So the tracing too gets in along with the cpu idle support. Thanks Ben. >> Cheers, >> Ben. >> >> >> _______________________________________________ >> Linuxppc-dev mailing list >> Linuxppc-dev@xxxxxxxxxxxxxxxx >> https://lists.ozlabs.org/listinfo/linuxppc-dev > > _______________________________________________ > Linuxppc-dev mailing list > Linuxppc-dev@xxxxxxxxxxxxxxxx > https://lists.ozlabs.org/listinfo/linuxppc-dev Regards, Deepthi _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
