diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index ebf723f33794e..0f3d01562ded2 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2257,7 +2257,10 @@ static int x86_pmu_event_idx(struct perf_event *event)
if (!(hwc->flags & PERF_X86_EVENT_RDPMC_ALLOWED))
return 0;
- return hwc->event_base_rdpmc + 1;
+ if (is_metric_idx(hwc->idx))
+ return INTEL_PMC_FIXED_RDPMC_METRICS + 1;
+ else
+ return hwc->event_base_rdpmc + 1;
}
static ssize_t get_attr_rdpmc(struct device *cdev,
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index db833346c119c..c72e4904e0567 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -2258,7 +2258,13 @@ static int icl_set_topdown_event_period(struct perf_event *event)
if (left == x86_pmu.max_period) {
wrmsrl(MSR_CORE_PERF_FIXED_CTR3, 0);
wrmsrl(MSR_PERF_METRICS, 0);
- local64_set(&hwc->period_left, 0);
+ hwc->saved_slots = 0;
+ hwc->saved_metric = 0;
+ }
+
+ if ((hwc->saved_slots) && is_slots_event(event)) {
+ wrmsrl(MSR_CORE_PERF_FIXED_CTR3, hwc->saved_slots);
+ wrmsrl(MSR_PERF_METRICS, hwc->saved_metric);
}
perf_event_update_userpage(event);
@@ -2279,7 +2285,7 @@ static inline u64 icl_get_metrics_event_value(u64 metric, u64 slots, int idx)
return mul_u64_u32_div(slots, val, 0xff);
}
-static void __icl_update_topdown_event(struct perf_event *event,
+static u64 icl_get_topdown_value(struct perf_event *event,
u64 slots, u64 metrics)
{
int idx = event->hw.idx;
@@ -2290,7 +2296,50 @@ static void __icl_update_topdown_event(struct perf_event *event,
else
delta = slots;
- local64_add(delta, &event->count);
+ return delta;
+}
+
+static void __icl_update_topdown_event(struct perf_event *event,
+ u64 slots, u64 metrics,
+ u64 last_slots, u64 last_metrics)
+{
+ u64 delta, last = 0;
+
+ delta = icl_get_topdown_value(event, slots, metrics);
+ if (last_slots)
+ last = icl_get_topdown_value(event, last_slots, last_metrics);
+
+ /*
+ * The 8bit integer fraction of metric may be not accurate,
+ * especially when the changes is very small.
+ * For example, if only a few bad_spec happens, the fraction
+ * may be reduced from 1 to 0. If so, the bad_spec event value
+ * will be 0 which is definitely less than the last value.
+ * Avoid update event->count for this case.
+ */
+ if (delta > last) {
+ delta -= last;
+ local64_add(delta, &event->count);
+ }
+}
+
+static void update_saved_topdown_regs(struct perf_event *event,
+ u64 slots, u64 metrics)
+{
+ struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
+ struct perf_event *other;
+ int idx;
+
+ event->hw.saved_slots = slots;
+ event->hw.saved_metric = metrics;
+
+ for_each_set_bit(idx, cpuc->active_mask, INTEL_PMC_IDX_TD_BE_BOUND + 1) {
+ if (!is_topdown_idx(idx))
+ continue;
+ other = cpuc->events[idx];
+ other->hw.saved_slots = slots;
+ other->hw.saved_metric = metrics;
+ }
}
/*
@@ -2304,6 +2353,7 @@ static u64 icl_update_topdown_event(struct perf_event *event)
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct perf_event *other;
u64 slots, metrics;
+ bool reset = true;
int idx;
/* read Fixed counter 3 */
@@ -2318,19 +2368,39 @@ static u64 icl_update_topdown_event(struct perf_event *event)
if (!is_topdown_idx(idx))
continue;
other = cpuc->events[idx];
- __icl_update_topdown_event(other, slots, metrics);
+ __icl_update_topdown_event(other, slots, metrics,
+ event ? event->hw.saved_slots : 0,
+ event ? event->hw.saved_metric : 0);
}
/*
* Check and update this event, which may have been cleared
* in active_mask e.g. x86_pmu_stop()
*/
- if (event && !test_bit(event->hw.idx, cpuc->active_mask))
- __icl_update_topdown_event(event, slots, metrics);
+ if (event && !test_bit(event->hw.idx, cpuc->active_mask)) {
+ __icl_update_topdown_event(event, slots, metrics,
+ event->hw.saved_slots,
+ event->hw.saved_metric);
- /* The fixed counter 3 has to be written before the PERF_METRICS. */
- wrmsrl(MSR_CORE_PERF_FIXED_CTR3, 0);
- wrmsrl(MSR_PERF_METRICS, 0);
+ /*
+ * In x86_pmu_stop(), the event is cleared in active_mask first,
+ * then drain the delta, which indicates context switch for
+ * counting.
+ * Save metric and slots for context switch.
+ * Don't need to reset the PERF_METRICS and Fixed counter 3.
+ * Because the values will be restored in next schedule in.
+ */
+ update_saved_topdown_regs(event, slots, metrics);
+ reset = false;
+ }
+
+ if (reset) {
+ /* The fixed counter 3 has to be written before the PERF_METRICS. */
+ wrmsrl(MSR_CORE_PERF_FIXED_CTR3, 0);
+ wrmsrl(MSR_PERF_METRICS, 0);
+ if (event)
+ update_saved_topdown_regs(event, 0, 0);
+ }
return slots;
}
@@ -3578,8 +3648,6 @@ static int intel_pmu_hw_config(struct perf_event *event)
*/
leader->hw.flags |= PERF_X86_EVENT_TOPDOWN;
event->hw.flags |= PERF_X86_EVENT_TOPDOWN;
-
- event->hw.flags &= ~PERF_X86_EVENT_RDPMC_ALLOWED;
}
}
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 6048650f8c1da..46a3974eb4fe6 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -212,17 +212,26 @@ struct hw_perf_event {
*/
u64 sample_period;
- /*
- * The period we started this sample with.
- */
- u64 last_period;
+ union {
+ struct { /* Sampling */
+ /*
+ * The period we started this sample with.
+ */
+ u64 last_period;
- /*
- * However much is left of the current period; note that this is
- * a full 64bit value and allows for generation of periods longer
- * than hardware might allow.
- */
- local64_t period_left;
+ /*
+ * However much is left of the current period;
+ * note that this is a full 64bit value and
+ * allows for generation of periods longer
+ * than hardware might allow.
+ */
+ local64_t period_left;
+ };
+ struct { /* Topdown events counting for context switch */
+ u64 saved_metric;
+ u64 saved_slots;
+ };
+ };
/*
* State for throttling the event, see __perf_event_overflow() and