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From: Peter Zijlstra <peterz@infradead.org>
To: mingo@kernel.org
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
	acme@kernel.org, mark.rutland@arm.com,
	alexander.shishkin@linux.intel.com, jolsa@kernel.org,
	namhyung@kernel.org, irogers@google.com, adrian.hunter@intel.com
Subject: [PATCH 11/13] perf: Simplify perf_adjust_freq_unthr_context()
Date: Thu, 02 Nov 2023 16:09:30 +0100	[thread overview]
Message-ID: <20231102152018.986157891@infradead.org> (raw)
In-Reply-To: 20231102150919.719936610@infradead.org


Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 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);
 }
 
 /*



  parent reply	other threads:[~2023-11-02 15:33 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-02 15:09 [PATCH 00/13] perf: Employ SBRM to simplify error handling -- batch 1/3 Peter Zijlstra
2023-11-02 15:09 ` [PATCH 01/13] perf: Simplify perf_event_alloc() error path Peter Zijlstra
2023-11-03 12:38   ` Jiri Olsa
2023-11-03 19:50     ` Namhyung Kim
2023-11-15  9:58       ` Peter Zijlstra
2023-11-15 15:12         ` Namhyung Kim
2023-11-15  9:31     ` Peter Zijlstra
2023-11-02 15:09 ` [PATCH 02/13] perf: Simplify perf_pmu_register() " Peter Zijlstra
2023-11-02 15:09 ` [PATCH 03/13] perf: Simplify perf_fget_light() Peter Zijlstra
2023-11-02 15:09 ` [PATCH 04/13] perf: Simplify event_function*() Peter Zijlstra
2023-11-02 15:09 ` [PATCH 05/13] perf: Simplify perf_cgroup_connect() Peter Zijlstra
2023-11-02 15:09 ` [PATCH 06/13] perf; Simplify event_sched_in() Peter Zijlstra
2023-11-02 15:09 ` [PATCH 07/13] perf: Simplify: __perf_install_in_context() Peter Zijlstra
2023-11-04  1:08   ` Namhyung Kim
2023-11-15  9:24     ` Peter Zijlstra
2023-11-02 15:09 ` [PATCH 08/13] perf: Simplify: *perf_event_{dis,en}able*() Peter Zijlstra
2023-11-02 15:09 ` [PATCH 09/13] perf: Simplify perf_event_modify_attr() Peter Zijlstra
2023-11-02 15:09 ` [PATCH 10/13] perf: Simplify perf_event_context_sched_in() Peter Zijlstra
2023-11-02 15:09 ` Peter Zijlstra [this message]
2023-11-04  1:14   ` [PATCH 11/13] perf: Simplify perf_adjust_freq_unthr_context() Namhyung Kim
2023-11-15 10:31     ` Peter Zijlstra
2023-11-02 15:09 ` [PATCH 12/13] perf: Simplify perf_event_*_on_exec() Peter Zijlstra
2023-11-02 15:09 ` [PATCH 13/13] perf: Simplify *perf_event_read*() Peter Zijlstra

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