build_packages: add option to automatically switch cpu governors
The powersave governor can take quite a while to get up to speed
when building things, so add a tip for users to automatically set
it to performance during the life of the build.
BUG=chromium:1008932
TEST=`./build_packages --noautosetgov` issues powersave warning
TEST=`./build_packages --autosetgov` switches to performance & then back to powersave
Change-Id: Ia56c1cccff68debef9928ade9800ee64e0f7ae0e
Reviewed-on: https://chromium-review.googlesource.com/1841944
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
diff --git a/build_packages b/build_packages
index e1e04d5..ed9e27b 100755
--- a/build_packages
+++ b/build_packages
@@ -32,6 +32,8 @@
"Define the file that event logs will be written."
DEFINE_boolean withrevdeps "${FLAGS_TRUE}" \
"Calculate reverse dependencies on changed ebuilds."
+DEFINE_boolean autosetgov "${FLAGS_FALSE}" \
+ "Automatically set cpu governor to 'performance'."
# The --board_root flag specifies the environment variables ROOT and PKGDIR.
# This allows fetching and emerging of all packages to specified board_root.
@@ -117,6 +119,25 @@
# Right now build_packages has to be run from scripts/
. ${SRC_ROOT}/third_party/chromiumos-overlay/chromeos/config/chromeos_version.sh
+# On some systems, powersave can take a long time to ramp up. Inform the user
+# so they can get faster builds. https://crbug.com/1008932
+if grep -qs powersave \
+ /sys/devices/system/cpu/cpufreq/policy*/scaling_governor; then
+ # Make sure we can actually support "performance".
+ if grep -qs performance \
+ /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors; then
+ if [[ "${FLAGS_autosetgov}" -eq "${FLAGS_TRUE}" ]]; then
+ info "Temporarily setting cpu governor to 'performance'"
+ trap "sudo cpupower -c all frequency-set -g powersave >&/dev/null" EXIT
+ sudo cpupower -c all frequency-set -g performance >&/dev/null
+ else
+ warn "Current CPU governor set to 'powersave' which can slow down builds."
+ warn "Use --autosetgov to automatically (and temporarily) switch to" \
+ "'performance'."
+ fi
+ fi
+fi
+
if [[ -z "${FLAGS_board}" ]]; then
echo "Error: --board is required."
exit 1
