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Subject[PATCH V3 4/5] perf/x86/intel: fix pmu read for large PEBS
Date
From: Kan Liang <kan.liang@linux.intel.com>

Large PEBS needs to be specially handled in event count read.

It is only available for intel_pmu.

Only need to specially handle the large PEBS. For the threshold is one,
even auto-reload is enabled, it doesn't need to be specially handled.
Because,
- auto-reload is only effect when event overflow. Once there is an
overflow, the NMI handler will automatically drain_pebs().
- For other cases, x86_perf_event_update() is good enough.

Fixes: b8241d20699e ("perf/x86/intel: Implement batched PEBS interrupt
handling (large PEBS interrupt threshold)")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
---
arch/x86/events/intel/core.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 731153a..1610a9d 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2060,6 +2060,14 @@ static void intel_pmu_del_event(struct perf_event *event)
intel_pmu_pebs_del(event);
}

+static void intel_pmu_read_event(struct perf_event *event)
+{
+ if (intel_pmu_large_pebs_read(event))
+ return;
+
+ x86_perf_event_update(event);
+}
+
static void intel_pmu_enable_fixed(struct hw_perf_event *hwc)
{
int idx = hwc->idx - INTEL_PMC_IDX_FIXED;
@@ -3495,6 +3503,7 @@ static __initconst const struct x86_pmu intel_pmu = {
.disable = intel_pmu_disable_event,
.add = intel_pmu_add_event,
.del = intel_pmu_del_event,
+ .read = intel_pmu_read_event,
.hw_config = intel_pmu_hw_config,
.schedule_events = x86_schedule_events,
.eventsel = MSR_ARCH_PERFMON_EVENTSEL0,
--
2.7.4
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