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Commit 63e6be6d authored by Robert Richter's avatar Robert Richter Committed by Ingo Molnar
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perf, x86: Catch spurious interrupts after disabling counters 



Some cpus still deliver spurious interrupts after disabling a
counter. This caused 'undelivered NMI' messages. This patch
fixes this. Introduced by:

  4177c42a: perf, x86: Try to handle unknown nmis with an enabled PMU

Reported-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarRobert Richter <robert.richter@amd.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: gorcunov@gmail.com <gorcunov@gmail.com>
Cc: fweisbec@gmail.com <fweisbec@gmail.com>
Cc: ying.huang@intel.com <ying.huang@intel.com>
Cc: ming.m.lin@intel.com <ming.m.lin@intel.com>
Cc: yinghai@kernel.org <yinghai@kernel.org>
Cc: andi@firstfloor.org <andi@firstfloor.org>
Cc: eranian@google.com <eranian@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20100915162034.GO13563@erda.amd.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 258af474

arch/x86/kernel/cpu/perf_event.c

+11 −1
Original line number Diff line number Diff line
@@ -102,6 +102,7 @@ struct cpu_hw_events { 
	 */

	struct perf_event	*events[X86_PMC_IDX_MAX]; /* in counter order */

	unsigned long		active_mask[BITS_TO_LONGS(X86_PMC_IDX_MAX)];

	unsigned long		running[BITS_TO_LONGS(X86_PMC_IDX_MAX)];

	int			enabled;



	int			n_events;
@@ -1010,6 +1011,7 @@ static int x86_pmu_start(struct perf_event *event) 
	x86_perf_event_set_period(event);

	cpuc->events[idx] = event;

	__set_bit(idx, cpuc->active_mask);

	__set_bit(idx, cpuc->running);

	x86_pmu.enable(event);

	perf_event_update_userpage(event);
@@ -1141,8 +1143,16 @@ static int x86_pmu_handle_irq(struct pt_regs *regs) 
	cpuc = &__get_cpu_var(cpu_hw_events);



	for (idx = 0; idx < x86_pmu.num_counters; idx++) {

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

		if (!test_bit(idx, cpuc->active_mask)) {

			/*

			 * Though we deactivated the counter some cpus

			 * might still deliver spurious interrupts still

			 * in flight. Catch them:

			 */

			if (__test_and_clear_bit(idx, cpuc->running))

				handled++;

			continue;

		}



		event = cpuc->events[idx];

		hwc = &event->hw;