linux-kernel - [PATCH] cpuidle: menu: Cleanup after loadavg removal

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Message-ID: <7d999005-4441-4b8a-b159-3d0ebc2ed9d9@arm.com>
Date: Tue, 4 Jun 2024 11:55:29 +0100
From: Christian Loehle <christian.loehle@....com>
To: "Rafael J. Wysocki" <rafael@...nel.org>,
 Daniel Lezcano <daniel.lezcano@...aro.org>
Cc: linux-pm@...r.kernel.org,
 "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: [PATCH] cpuidle: menu: Cleanup after loadavg removal

The performance impact of loadavg was removed with commit a7fe5190c03f
("cpuidle: menu: Remove get_loadavg() from the performance multiplier")
With only iowait remaining the description can be simplified, remove
also the no longer needed includes.

Signed-off-by: Christian Loehle <christian.loehle@....com>
---
 drivers/cpuidle/governors/menu.c | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index b96e3da0fedd..783b5d1dacdc 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -14,8 +14,6 @@
 #include <linux/ktime.h>
 #include <linux/hrtimer.h>
 #include <linux/tick.h>
-#include <linux/sched.h>
-#include <linux/sched/loadavg.h>
 #include <linux/sched/stat.h>
 #include <linux/math64.h>
 
@@ -95,16 +93,11 @@
  * state, and thus the less likely a busy CPU will hit such a deep
  * C state.
  *
- * Two factors are used in determing this multiplier:
- * a value of 10 is added for each point of "per cpu load average" we have.
- * a value of 5 points is added for each process that is waiting for
- * IO on this CPU.
- * (these values are experimentally determined)
- *
- * The load average factor gives a longer term (few seconds) input to the
- * decision, while the iowait value gives a cpu local instantanious input.
- * The iowait factor may look low, but realize that this is also already
- * represented in the system load average.
+ * Currently there is only one value determining the factor:
+ * 10 points are added for each process that is waiting for IO on this CPU.
+ * (This value was experimentally determined.)
+ * Utilization is no longer a factor as it was shown that it never contributed
+ * significantly to the performance multiplier in the first place.
  *
  */
 
-- 
2.34.1