From d43da88de72dc2716d63c41fe5bd4e317c4e9ca7 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Thu, 4 Jan 2024 15:07:31 +0100
Subject: [cpugovernor] Update script, handle different drivers

---
 .../data/opt/openslx/scripts/systemd-cpu_governor  | 83 +++++++++-------------
 1 file changed, 33 insertions(+), 50 deletions(-)

diff --git a/core/modules/cpugovernor/data/opt/openslx/scripts/systemd-cpu_governor b/core/modules/cpugovernor/data/opt/openslx/scripts/systemd-cpu_governor
index f7aa255a..cdde82d5 100755
--- a/core/modules/cpugovernor/data/opt/openslx/scripts/systemd-cpu_governor
+++ b/core/modules/cpugovernor/data/opt/openslx/scripts/systemd-cpu_governor
@@ -7,56 +7,39 @@
 . /opt/openslx/config || \
 	{ echo "ERROR: Could not source /opt/openslx/config."; exit 1; }
 
-# set the governor to the one given in SLX_GOVERNOR
-TARGET_GOVERNOR=""
-if [ -n "$SLX_GOVERNOR" ]; then
-	TARGET_GOVERNOR="$SLX_GOVERNOR"
-else
-	# use 'ondemand' per default
-	TARGET_GOVERNOR="ondemand"
-fi
-echo "Trying to set CPU governor to $TARGET_GOVERNOR"
-# global information needed
-# CORES is the range of cores present, on bwpc4 it has the value '0-3'
-# thus the split: MINCORE=0 MAXCORE=3
-CORES="$(cat /sys/devices/system/cpu/present)"
-MINCORE="$(echo $CORES | awk -F "-" '{print $1}')"
-MAXCORE="$(echo $CORES | awk -F "-" '{print $2}')"
+# if scaling_driver is acpi-cpufreq:
+#   cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
+#   conservative ondemand userspace powersave performance schedutil
+#   -> use ondemand and performance
+# if scaling_driver is intel_cpufreq:
+#   cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
+#   conservative ondemand userspace powersave performance schedutil
+#   -> same as acpi
+# if scaling_driver is intel_pstate:
+#   cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
+#   performance powersave
+#   -> we only got two choices anyways :)
+# if scaling_driver is amd_pstate:
+#   haven't seen this yet, relatively new as of 2024, but it should work
+#   almost the same as intel_pstate, i.e. only performance and powersave
 
-# Helper function 'test_for_gov'
-# Usage:
-#	test_for_gov <governor>
-# Example:
-#	test_for_gov "ondemand"
-# Return 0 if it is supported by all cpus, 1 otherwise
-test_for_gov() {
-	# if no argument is given, print error and exit (yes exit the whole script!)
-	[ $# -ne 1 ] && echo "Usage: test_for_gov <governor>. No arguments given!" && exit 1
-	local GOVERNOR="$1"
-
-	# check for each cpu just to be safe
-	# ash-style loop ....
-	local i=$MINCORE
-	while [ $i -le $MAXCORE ]; do
-		# check if the given governor is supported
-		grep -q "${GOVERNOR}" /sys/devices/system/cpu/cpu${i}/cpufreq/scaling_available_governors 2>/dev/null || return 1;
-		# increment
-		true $(( i++ ))
-	done
-	return 0;
-}
-# now actually test the cpus for the 'ondemand' cpu governor
-if test_for_gov "${TARGET_GOVERNOR}"; then
-	# ok, so now set the governor to 'ondemand' for all cores
-	i=$MINCORE
-	while [ $i -le $MAXCORE ]; do
-		if ! echo "${TARGET_GOVERNOR}" > /sys/devices/system/cpu/cpu${i}/cpufreq/scaling_governor; then
-			echo "ERROR: Could not set the cpu governor to '${TARGET_GOVERNOR}'!"
-			exit 1
-		fi
-		true $(( i++ ))
-	done
+# set the governor. Prioritize command-line argument, then SLX_GOVERNOR,
+# fall back to powersave.
+if [ -n "$1" ]; then
+	wanted_gov="$1"
+elif [ -n "$SLX_GOVERNOR" ]; then
+	wanted_gov="$SLX_GOVERNOR"
 else
-	echo "ERROR: '${TARGET_GOVERNOR}' is not supported by this machine!"
-	exit 0
+	wanted_gov="powersave"
 fi
+echo "Trying to set CPU governor to $wanted_gov"
+
+for dir in /sys/devices/system/cpu/cpu*/cpufreq; do
+	driver=$( cat "$dir/scaling_driver" )
+	newgov="$wanted_gov"
+	if [ "$driver" != "intel_pstate" ] && [ "$driver" != "amd_pstate" ]; then
+		[ "$newgov" = "powersave" ] && newgov="ondemand"
+	fi
+	echo "$newgov" > "$dir/scaling_governor"
+done
+exit 0
-- 
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