Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 71e2d282 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

perf, x86: Avoid double disable on throttle vs ioctl(PERF_IOC_DISABLE) 



Calling ioctl(PERF_EVENT_IOC_DISABLE) on a thottled counter would result
in a double disable, cure this by using x86_pmu_{start,stop} for
throttle/unthrottle and teach x86_pmu_stop() to check ->active_mask.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: paulus@samba.org
Cc: eranian@google.com
Cc: robert.richter@amd.com
Cc: fweisbec@gmail.com
LKML-Reference: <new-submission>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent c08053e6

arch/x86/kernel/cpu/perf_event.c

+6 −14
Original line number Diff line number Diff line
@@ -983,14 +983,8 @@ static int x86_pmu_start(struct perf_event *event) 


static void x86_pmu_unthrottle(struct perf_event *event)

{

	struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);

	struct hw_perf_event *hwc = &event->hw;



	if (WARN_ON_ONCE(hwc->idx >= X86_PMC_IDX_MAX ||

				cpuc->events[hwc->idx] != event))

		return;



	x86_pmu.enable(event);

	int ret = x86_pmu_start(event);

	WARN_ON_ONCE(ret);

}



void perf_event_print_debug(void)
@@ -1050,11 +1044,9 @@ static void x86_pmu_stop(struct perf_event *event) 
	struct hw_perf_event *hwc = &event->hw;

	int idx = hwc->idx;



	/*

	 * Must be done before we disable, otherwise the nmi handler

	 * could reenable again:

	 */

	__clear_bit(idx, cpuc->active_mask);

	if (!__test_and_clear_bit(idx, cpuc->active_mask))

		return;



	x86_pmu.disable(event);



	/*
@@ -1123,7 +1115,7 @@ static int x86_pmu_handle_irq(struct pt_regs *regs) 
			continue;



		if (perf_event_overflow(event, 1, &data, regs))

			x86_pmu.disable(event);

			x86_pmu_stop(event);

	}



	if (handled)

arch/x86/kernel/cpu/perf_event_intel.c

+1 −1
Original line number Diff line number Diff line
@@ -774,7 +774,7 @@ static int intel_pmu_handle_irq(struct pt_regs *regs) 
		data.period = event->hw.last_period;



		if (perf_event_overflow(event, 1, &data, regs))

			intel_pmu_disable_event(event);

			x86_pmu_stop(event);

	}



	intel_pmu_ack_status(ack);