From c87ac216a971ae33582eda9dbf1c980b356feae9 Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Mon, 18 Dec 2023 20:08:06 -0500
Subject: [PATCH] Set the energy performance preference for AMD.

---
 .../cpu/files/cpu_set_perf_perc_linux_amd     | 21 ++++++++++++++++
 ...rc_linux => cpu_set_perf_perc_linux_intel} |  0
 ansible/roles/cpu/tasks/linux_amd.yaml        | 24 +++++++++++++++++++
 ansible/roles/cpu/tasks/linux_intel.yaml      |  2 +-
 .../energy_performance_preference.conf.j2     |  2 +-
 5 files changed, 47 insertions(+), 2 deletions(-)
 create mode 100644 ansible/roles/cpu/files/cpu_set_perf_perc_linux_amd
 rename ansible/roles/cpu/files/{cpu_set_perf_perc_linux => cpu_set_perf_perc_linux_intel} (100%)

diff --git a/ansible/roles/cpu/files/cpu_set_perf_perc_linux_amd b/ansible/roles/cpu/files/cpu_set_perf_perc_linux_amd
new file mode 100644
index 0000000..74d04b1
--- /dev/null
+++ b/ansible/roles/cpu/files/cpu_set_perf_perc_linux_amd
@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+#
+# Tell hardware p-states whether to maximize CPU performance (100) or
+# energy efficiency (0).
+set -euo pipefail
+IFS=$'\n\t'
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+perc=$1
+
+if [ "$perc" -ge 80 ]; then
+    echo "performance" | tee /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
+elif [ "$perc" -ge 60 ]; then
+    echo "balance_performance" | tee /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
+elif [ "$perc" -ge 40 ]; then
+    echo "default" | tee /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
+elif [ "$perc" -ge 20 ]; then
+    echo "balance_power" | tee /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
+else
+    echo "power" | tee /sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
+fi
diff --git a/ansible/roles/cpu/files/cpu_set_perf_perc_linux b/ansible/roles/cpu/files/cpu_set_perf_perc_linux_intel
similarity index 100%
rename from ansible/roles/cpu/files/cpu_set_perf_perc_linux
rename to ansible/roles/cpu/files/cpu_set_perf_perc_linux_intel
diff --git a/ansible/roles/cpu/tasks/linux_amd.yaml b/ansible/roles/cpu/tasks/linux_amd.yaml
index b521f5a..fa1c279 100644
--- a/ansible/roles/cpu/tasks/linux_amd.yaml
+++ b/ansible/roles/cpu/tasks/linux_amd.yaml
@@ -3,3 +3,27 @@
     name:
       - powertop
     state: present
+
+- name: Favor energy efficiency for Speed Shift
+  when: hwpstate is defined and hwpstate and cores is defined
+  template:
+    src: "templates/{{ item.src }}.j2"
+    dest: "{{ item.dest }}"
+    mode: 0755
+    owner: root
+    group: wheel
+  loop:
+    - src: energy_performance_preference.conf
+      dest: /etc/tmpfiles.d/energy_performance_preference.conf
+
+- name: Install scripts
+  when: hwpstate is defined and hwpstate
+  copy:
+    src: "files/{{ item.src }}"
+    dest: "{{ item.dest }}"
+    mode: 0755
+    owner: root
+    group: wheel
+  loop:
+    - src: cpu_set_perf_perc_linux_amd
+      dest: /usr/local/bin/cpu_set_perf_perc
diff --git a/ansible/roles/cpu/tasks/linux_intel.yaml b/ansible/roles/cpu/tasks/linux_intel.yaml
index f49196c..6cac6c5 100644
--- a/ansible/roles/cpu/tasks/linux_intel.yaml
+++ b/ansible/roles/cpu/tasks/linux_intel.yaml
@@ -35,5 +35,5 @@
     owner: root
     group: wheel
   loop:
-    - src: cpu_set_perf_perc_linux
+    - src: cpu_set_perf_perc_linux_intel
       dest: /usr/local/bin/cpu_set_perf_perc
diff --git a/ansible/roles/cpu/templates/energy_performance_preference.conf.j2 b/ansible/roles/cpu/templates/energy_performance_preference.conf.j2
index b5a4239..bb97375 100644
--- a/ansible/roles/cpu/templates/energy_performance_preference.conf.j2
+++ b/ansible/roles/cpu/templates/energy_performance_preference.conf.j2
@@ -1,4 +1,4 @@
-# Favor energy efficiency for Speed Shift
+# Favor energy efficiency for hardware p-states
 {% for core in range(0, cores, 1) %}
 w- /sys/devices/system/cpu/cpufreq/policy{{core}}/energy_performance_preference - - - - power
 {% endfor %}