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authorStephane Eranian <eranian@google.com>2012-02-02 12:04:01 +0100
committerIngo Molnar <mingo@elte.hu>2012-02-03 08:24:40 +0100
commit84f2b9b2edc09595569c7397cc3c888764ffd78b (patch)
treef959f7f5746b3dc8409b2aae9584101c9b2f71a1 /tools
parent6c073a7ee250118b8be3a2379c96fd7f78382b06 (diff)
downloadop-kernel-dev-84f2b9b2edc09595569c7397cc3c888764ffd78b.zip
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perf: Remove deprecated WARN_ON_ONCE()
With the new throttling/unthrottling code introduced with commit: e050e3f0a71b ("perf: Fix broken interrupt rate throttling") we occasionally hit two WARN_ON_ONCE() checks in: - intel_pmu_pebs_enable() - intel_pmu_lbr_enable() - x86_pmu_start() The assertions are no longer problematic. There is a valid path where they can trigger but it is harmless. The assertion can be triggered with: $ perf record -e instructions:pp .... Leading to paths: intel_pmu_pebs_enable intel_pmu_enable_event x86_perf_event_set_period x86_pmu_start perf_adjust_freq_unthr_context perf_event_task_tick scheduler_tick And: intel_pmu_lbr_enable intel_pmu_enable_event x86_perf_event_set_period x86_pmu_start perf_adjust_freq_unthr_context. perf_event_task_tick scheduler_tick cpuc->enabled is always on because when we get to perf_adjust_freq_unthr_context() the PMU is not totally disabled. Furthermore when we need to adjust a period, we only stop the event we need to change and not the entire PMU. Thus, when we re-enable, cpuc->enabled is already set. Note that when we stop the event, both pebs and lbr are stopped if necessary (and possible). Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Link: http://lkml.kernel.org/r/20120202110401.GA30911@quad Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'tools')
0 files changed, 0 insertions, 0 deletions
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