Backup/restore CPU configuration before/after running benchmarks.

Change-Id: I611bc1e1ed09b10663f91920a49c2830cd142439

1 files changed, 38 insertions, 0 deletions

diff --git a/devices/cpu_freq_utils.sh b/devices/cpu_freq_utils.sh
index 8132542..c31ac73 100644
--- a/devices/cpu_freq_utils.sh
+++ b/devices/cpu_freq_utils.sh
@@ -129,3 +129,41 @@ get_device_settings() {
 
   safe source "${cpu_freq_script}"
 }
+
+# Arguments:
+#   ${1} - backup directory
+backup_device_cpus_config() {
+  local -r backup_dir="${1}"
+  for remote_cpu_path in $(adb_shell_strip echo "$sys_cpu_path/cpu*"); do
+    if [[ $remote_cpu_path =~ .*cpu([0-9]+)$ ]]; then
+      local cpu_index=${BASH_REMATCH[1]}
+      local local_cpu_path="$backup_dir/cpu$cpu_index"
+      safe mkdir -p "$local_cpu_path/cpufreq"
+      adb pull "$remote_cpu_path/online" "$local_cpu_path"
+      adb pull "$remote_cpu_path/cpufreq/scaling_governor" "$local_cpu_path/cpufreq/"
+      adb pull "$remote_cpu_path/cpufreq/scaling_setspeed" "$local_cpu_path/cpufreq/"
+    fi
+  done
+}
+
+
+# Arguments:
+#   $1 - backup directory
+restore_device_cpus_config() {
+  local -r backup_dir="${1}"
+  for local_cpu_path in "$backup_dir"/*; do
+    local cpu_index=${local_cpu_path#${backup_dir}/cpu}
+    local remote_cpu_path="$sys_cpu_path/cpu$cpu_index"
+    # Note that we do not use `safe` for `online` and `scaling_setspeed`,
+    # because attempting to set those to their current value raises an error.
+    adb shell "echo \"$(cat "$local_cpu_path/online")\" > $remote_cpu_path/online"
+    if [[ -f "$local_cpu_path/cpufreq/scaling_governor" ]]; then
+      safe adb shell "echo \"$(cat "$local_cpu_path/cpufreq/scaling_governor")\" > $remote_cpu_path/cpufreq/scaling_governor"
+    fi
+    local freq=$(cat "$local_cpu_path/cpufreq/scaling_setspeed")
+    if [[ "$freq" =~ ^[0-9]+$ ]]; then
+      adb shell "echo \"$freq\" > $remote_cpu_path/cpufreq/scaling_setspeed"
+    fi
+  done
+  rm -rf "$backup_dir"
+}