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authorRobert Richter <robert.richter@amd.com>2010-09-15 18:20:34 +0200
committerIngo Molnar <mingo@elte.hu>2010-09-24 12:21:41 +0200
commit63e6be6d98e1a2bcdca86872b67052e51ab6afa1 (patch)
treec7aa3de767ab2f5441c66bdd3ad38cf3b60306ee
parent258af47479980d8238a04568b94a4e55aa1cb537 (diff)
downloadlinux-63e6be6d98e1a2bcdca86872b67052e51ab6afa1.tar.bz2
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: 4177c42: perf, x86: Try to handle unknown nmis with an enabled PMU Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Robert 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: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/cpu/perf_event.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 3efdf2870a35..03a5b0385ad6 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -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;