On 28 February 2011 16:30, Jean Pihet <jean.pihet@xxxxxxxxxxxxxx> wrote: > Hi Pierre, > > On Mon, Feb 28, 2011 at 4:09 PM, Pierre Tardy <tardyp@xxxxxxxxx> wrote: >> On Mon, Feb 28, 2011 at 2:43 PM, Vincent Guittot >> <vincent.guittot@xxxxxxxxxx> wrote: >>> On 27 February 2011 17:31, Pierre Tardy <tardyp@xxxxxxxxx> wrote: >>>> On Fri, Feb 18, 2011 at 11:03 AM, Vincent Guittot >>>> <vincent.guittot@xxxxxxxxxx> wrote: >>>>> Hi, >>>>> >>>>> I have started to use the new cpuidle tracepoint and created a plugin >>>>> for pytimechart. >>>>> I'm not sure if it's the right way to add this cpuidle trace format >>>>> update but it's the less intrusive one. >>>> >>>> Yes, it is okay. I actually plan to also put the whole cpuidle trace >>>> handling into such plugin. >>>> Would you care to send me one of your trace file, so that I can >>>> actually test it. >>> >>> Yes, I have attached the trace file which is Vishwa's one in fact. >> Thanks, I applied and pushed the patch. >> >> Please note that your trace has some suspicious tracepoints with same >> timestamps for end of cpuidle and start of next cpuidle. > That comes from a known problem about the timer on OMAP. The 32K timer > is feeding the trace timestamps and so the granularity is not high > enough (30us). > >> <idle>-0 [000] 270.645935: cpu_idle: state=2 cpu_id=0 >> <idle>-0 [000] 271.020935: cpu_idle: state=4294967295 cpu_id=0 >> <idle>-0 [000] 271.020935: cpu_idle: state=2 cpu_id=0 >> <idle>-0 [000] 271.036560: cpu_idle: state=4294967295 cpu_id=0 >> <idle>-0 [000] 271.073395: cpu_idle: state=1 cpu_id=0 >> >> >> Also, cpuidle states name in pytimechart are very selfishly hardcoded >> with intel's convention. >> Can you tell what is your convention, so that we can think of a best >> way to handle display of state's name for ftrace text output? > The power trace points API is described in Documentation/trace/events-power.txt. > > Here is an excerpt of it: > " > The value of '-1' or '4294967295' for state means an exit from the > current state, > i.e. trace_cpu_idle(4, smp_processor_id()) means that the system > enters the idle state 4, while trace_cpu_idle(PWR_EVENT_EXIT, > smp_processor_id()) > means that the system exits the previous idle state. > > The event which has 'state=4294967295' in the trace is very important > to the user > space tools which are using it to detect the end of the current state, and so to > correctly draw the states diagrams and to calculate accurate statistics etc. > " > > I would be glad to help on pytimechart, please let me know! > We currently have no consistent state name description across arm platform but I hope we will have soon. May be displaying them as C0, C1 and so on should be a solution until we have a common description of idle state across arm platform. Regards, Vincent > Regards, > Jean > >> >> Regards, >> Pierre >> >> _______________________________________________ >> linaro-dev mailing list >> linaro-dev@xxxxxxxxxxxxxxxx >> http://lists.linaro.org/mailman/listinfo/linaro-dev >> > -- To unsubscribe from this list: send the line "unsubscribe linux-trace-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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