[PATCH 11/13] perf: Simplify perf_adjust_freq_unthr_context()

Peter Zijlstra
2023-11-02T15:33:03Z

kernel/events/core.c | 51 +++++++++++++++++++++++----------------------------
1 file changed, 23 insertions(+), 28 deletions(-)

--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4090,7 +4090,7 @@ perf_adjust_freq_unthr_context(struct pe
if (!(ctx->nr_freq || unthrottle))
return;

- raw_spin_lock(&ctx->lock);
+ guard(raw_spinlock)(&ctx->lock);

list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
if (event->state != PERF_EVENT_STATE_ACTIVE)
@@ -4100,7 +4100,7 @@ perf_adjust_freq_unthr_context(struct pe
if (!event_filter_match(event))
continue;

- perf_pmu_disable(event->pmu);
+ guard(perf_pmu_disable)(event->pmu);

hwc = &event->hw;

@@ -4110,34 +4110,29 @@ perf_adjust_freq_unthr_context(struct pe
event->pmu->start(event, 0);
}

- if (!event->attr.freq || !event->attr.sample_freq)
- goto next;
+ if (event->attr.freq && event->attr.sample_freq) {
+ /*
+ * stop the event and update event->count
+ */
+ event->pmu->stop(event, PERF_EF_UPDATE);
+
+ now = local64_read(&event->count);
+ delta = now - hwc->freq_count_stamp;
+ hwc->freq_count_stamp = now;
+
+ /*
+ * restart the event
+ * reload only if value has changed
+ * we have stopped the event so tell that
+ * to perf_adjust_period() to avoid stopping it
+ * twice.
+ */
+ if (delta > 0)
+ perf_adjust_period(event, period, delta, false);

- /*
- * stop the event and update event->count
- */
- event->pmu->stop(event, PERF_EF_UPDATE);
-
- now = local64_read(&event->count);
- delta = now - hwc->freq_count_stamp;
- hwc->freq_count_stamp = now;
-
- /*
- * restart the event
- * reload only if value has changed
- * we have stopped the event so tell that
- * to perf_adjust_period() to avoid stopping it
- * twice.
- */
- if (delta > 0)
- perf_adjust_period(event, period, delta, false);
-
- event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
- next:
- perf_pmu_enable(event->pmu);
+ event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
+ }
}
-
- raw_spin_unlock(&ctx->lock);
}

/*