Messages in this thread | | | Date | Tue, 31 Aug 2010 10:03:33 +0200 | Subject | Re: [tip:perf/urgent] perf_events: Fix time tracking for events with pid != -1 and cpu != -1 | From | stephane eranian <> |
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On Tue, Aug 31, 2010 at 3:10 AM, Lin Ming <lin@ming.vg> wrote: >> >> perf_events: Fix time tracking for events with pid != -1 and cpu != -1 > > Hi, > > I thought pid != -1 and cpu != -1 is not valid. >
This is in per-thread mode. This is what happens when you do perf record foo for instance. This is sampling, but you can do the same with counting.
> # perf top -p 23268 -C 1 > WARNING: PID switch overriding CPU > > In which case this could be valid? > > Thanks, > Lin Ming > >> >> Per-thread events with a cpu filter, i.e., cpu != -1, were not >> reporting correct timings when the thread never ran on the >> monitored cpu. The time enabled was reported as a negative >> value. >
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