On (10/07/13 19:31), Shaojie Sun wrote: > Date: Mon, 7 Oct 2013 19:31:54 +0800 > From: Shaojie Sun <shaojie.sun(a)linaro.org&gt; > To: Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com&gt; > Cc: Sanjay Rawat <sanjay.rawat(a)linaro.org&gt;, Jon Medhurst <tixy(a)linaro.org&gt;, > SunShaoJie <sunshaojie(a)huawei.com&gt;, "Private-PMWG@Linaro" > <private-pmwg(a)linaro.org&gt; > Subject: Re: [Powertop] [PATCH POWERTOP V3] resolve the bug that powertop > doesn't show correct frequency stats > > Goog question. > Could Tixy answer it? /** Removed Private-PMWG (no permissions), Cc'd powertop list. */ the thing is that we tend to trust passed cpunr in many handle_trace_point()-s. so it would be better to fix all sample->trace.cpu users, because the problme may be a bit bigger than that (e.g. src/process/do_process.cpp perf_process_bundle::handle_trace_point()). -ss > On Mon, Oct 7, 2013 at 6:03 PM, Sergey Senozhatsky > <sergey.senozhatsky(a)gmail.com&gt; wrote: > > On (10/07/13 17:26), Shaojie Sun wrote: > >> From: Jon Medhurst <tixy(a)linaro.org&gt; > >> > >> For cpu_frequency events, perf_power_bundle::handle_trace_point() > >> is always being called with the same cpunr. so the parameter of > >> cpunr is not equal to the cpu which cpu_frequency events happened. > >> Lucky the trace event themselves have a cpu_id field to say to which > >> CPU event it relates, we should use this cpu_id field. > >> > >> Signed-off-by: Jon Medhurst <tixy(a)linaro.org&gt; > >> Shaojie Sun <shaojie.sun(a)linaro.com&gt; > >> --- > >> src/cpu/cpu.cpp | 9 +++++++-- > >> 1 file changed, 7 insertions(+), 2 deletions(-) > >> > >> diff --git a/src/cpu/cpu.cpp b/src/cpu/cpu.cpp > >> index 7f3af69..e304bbe 100644 > >> --- a/src/cpu/cpu.cpp > >> +++ b/src/cpu/cpu.cpp > >> @@ -781,10 +781,15 @@ void perf_power_bundle::handle_trace_point(void *trace, int cpunr, uint64_t time > >> > >> if (strcmp(event->name, "power_frequency") == 0 > >> || strcmp(event->name, "cpu_frequency") == 0){ > >> - > >> + ret = pevent_get_field_val(NULL, event, "cpu_id", &rec, &val, 0); > >> + if (ret < 0) { > >> + fprintf(stderr, _("power or cpu_frequency event returned no cpu?\n")); > >> + exit(-1); > >> + } > >> + cpu = all_cpus[val]; > >> ret = pevent_get_field_val(NULL, event, "state", &rec, &val, 0); > >> if (ret < 0) { > >> - fprintf(stderr, _("power or cpu_frequecny event returned no state?\n")); > >> + fprintf(stderr, _("power or cpu_frequency event returned no state?\n")); > >> exit(-1); > >> } > > > > Hello, > > why not fixing it in src/perf/perf_bundle (perf_sample's perf_event_header), > > where we create data for handle_trace_point() ? > > > > -ss > > > >> -- > >> 1.7.9.5 > >> > >> _______________________________________________ > >> PowerTop mailing list > >> PowerTop(a)lists.01.org > >> https://lists.01.org/mailman/listinfo/powertop > >> >