Messages in this thread | | | From | Cong Wang <> | Date | Mon, 23 Jul 2018 18:35:54 -0700 | Subject | Re: [PATCH v2] perf/core: fix a possible deadlock scenario |
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Hi, Peter, Andi
While reviewing the deadlock, I find out it looks like we could have the following infinite recursion too:
perf_event_account_interrupt() __perf_event_account_interrupt() perf_adjust_period() event->pmu->stop x86_pmu_stop() x86_pmu.disable() intel_pmu_disable_event() intel_pmu_pebs_disable() intel_pmu_drain_pebs_buffer() intel_pmu_drain_pebs_nhm() <repeat....>
This time is pure hardware events, attr.freq must be non-zero.
And, we could enter this infinite recursion in NMI handler too:
intel_pmu_handle_irq() perf_event_overflow() __perf_event_overflow() __perf_event_account_interrupt() ....
Or this is impossible too?
Thanks!
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