Messages in this thread | | | Date | Mon, 6 Feb 2012 15:38:45 +0100 | From | Ingo Molnar <> | Subject | Re: WARNING: at arch/x86/kernel/cpu/perf_event.c:989 |
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* Stephane Eranian <eranian@google.com> wrote:
> Ok, I found the problem! > > it comes from perf_adjust_freq_unthr_context() vs perf_adjust_period(). > The latter can under certain condition stop and restart the event. So we > had: > > stop() > if (delta > 0) { > perf_adjust_period() { > if (period > 8*...) { > stop() > ... > start() > } > } > } > start() > > Could have a double stop() and double start(), thus triggering the warning in > x86_pmu_start(). > > Will post a patch shortly to fix this.
Please send a patch against tip:master (or perf/urgent), on top of:
84f2b9b2edc0: perf: Remove deprecated WARN_ON_ONCE()
Note that I updated that patch to removed one more WARN_ON() than you originally sent - please add it back as appropriate, in the delta fix patch.
Thanks,
Ingo
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