linux-kernel - [PATCH v1 8/9] cpuidle: teo: Simplify handling of total events count

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Message-ID: <9388883.CDJkKcVGEf@rjwysocki.net>
Date: Mon, 13 Jan 2025 19:50:23 +0100
From: "Rafael J. Wysocki" <rjw@...ysocki.net>
To: Linux PM <linux-pm@...r.kernel.org>
Cc: LKML <linux-kernel@...r.kernel.org>,
 Daniel Lezcano <daniel.lezcano@...aro.org>,
 Christian Loehle <christian.loehle@....com>,
 Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>
Subject: [PATCH v1 8/9] cpuidle: teo: Simplify handling of total events count

From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>

Instead of computing the total events count from scratch every time,
decay it and add a PULSE value to it in teo_update().

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/cpuidle/governors/teo.c |    5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

--- a/drivers/cpuidle/governors/teo.c
+++ b/drivers/cpuidle/governors/teo.c
@@ -189,8 +189,6 @@
 		}
 	}

-	cpu_data->total = 0;
-
 	/*
 	 * Decay the "hits" and "intercepts" metrics for all of the bins and
 	 * find the bins that the sleep length and the measured idle duration
@@ -202,8 +200,6 @@
 		bin->hits -= bin->hits >> DECAY_SHIFT;
 		bin->intercepts -= bin->intercepts >> DECAY_SHIFT;

-		cpu_data->total += bin->hits + bin->intercepts;
-
 		target_residency_ns = drv->states[i].target_residency_ns;

 		if (target_residency_ns <= cpu_data->sleep_length_ns) {
@@ -228,6 +224,7 @@
 			cpu_data->tick_intercepts += PULSE;
 	}

+	cpu_data->total -= cpu_data->total >> DECAY_SHIFT;
 	cpu_data->total += PULSE;
 }