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);
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;
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;
+ }
}
/*
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 */
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;
}
*/
leader->hw.flags |= PERF_X86_EVENT_TOPDOWN;
event->hw.flags |= PERF_X86_EVENT_TOPDOWN;
-
- event->hw.flags &= ~PERF_X86_EVENT_RDPMC_ALLOWED;
}
}