From: Xunlei Pang pang.xunlei@linaro.org

DVFS adds a latency in the execution of task because of the time to decide to move at max freq. We need to measure this latency and check that the governor stays in an acceptable range.

When workgen runs a json file, a log file is created for each thread. This log file records the number of loop that has been executed and the duration for executing these loops (per phase). We can use these figures to evaluate to latency that is added by a cpufreq governor and its "performance efficiency".

We use the run+sleep pattern to do the measurement, for the run time per loop, the performance governor should run the expected duration as the CPU stays a max freq. At the opposite, the powersave governor will give use the longest duration (as it stays at lowest OPP). Other governor will be somewhere between the 2 previous duration as they will use several OPP and will go back to max frequency after a defined duration which depends on its monitoring period.

The formula:

duration of powersave gov - duration of the gov -------------------------------------------------------- x 100% duration of powersave gov - duration of performance gov

will give the efficiency of the governor. 100% means as efficient as the perf governor and 0% means as efficient as the powersave governor.

This patch offers json files and shell scripts to do the measurement,

Usage: ./test.sh <cpus> <runtime> <sleeptime> cpus: number of cpus in the CPU0's frequency domain runtime: running time in ms per loop of the workload pattern sleeptime: sleeping time in ms per loop of the workload pattern

Example: "./test.sh 4 100 1000" means CPU0~CPU3 sharing frequency, "100ms run + 1000ms sleep" workload pattern.

test result on my machine: ~#./test.sh 4 100 1000 Frequency domain CPU0~CPU3, run 100ms, sleep 1000ms: powersave efficiency: 0% performance efficiency: 100% conservative efficiency: 28% ondemand efficiency: 95%

NOTE: Make sure there are "sed", "cut", "grep", "rt-app", etc tools on your test machine, and run the script under root privilege.

Signed-off-by: Xunlei Pang pang.xunlei@linaro.org --- .../cpufreq_governor_efficiency/calibration.json | 27 +++++++ .../cpufreq_governor_efficiency/calibration.sh | 11 +++ doc/examples/cpufreq_governor_efficiency/dvfs.json | 27 +++++++ doc/examples/cpufreq_governor_efficiency/dvfs.sh | 38 ++++++++++ doc/examples/cpufreq_governor_efficiency/test.sh | 82 ++++++++++++++++++++++ 5 files changed, 185 insertions(+) create mode 100644 doc/examples/cpufreq_governor_efficiency/calibration.json create mode 100755 doc/examples/cpufreq_governor_efficiency/calibration.sh create mode 100644 doc/examples/cpufreq_governor_efficiency/dvfs.json create mode 100755 doc/examples/cpufreq_governor_efficiency/dvfs.sh create mode 100755 doc/examples/cpufreq_governor_efficiency/test.sh

diff --git a/doc/examples/cpufreq_governor_efficiency/calibration.json b/doc/examples/cpufreq_governor_efficiency/calibration.json new file mode 100644 index 0000000..4377990 --- /dev/null +++ b/doc/examples/cpufreq_governor_efficiency/calibration.json @@ -0,0 +1,27 @@ +{ + "tasks" : { + "thread" : { + "instance" : 1, + "cpus" : [0], + "loop" : 1, + "phases" : { + "run" : { + "loop" : 1, + "run" : 200000, + }, + "sleep" : { + "loop" : 1, + "sleep" : 200000, + } + } + } + }, + "global" : { + "default_policy" : "SCHED_FIFO", + "calibration" : "CPU0", + "lock_pages" : true, + "ftrace" : true, + "logdir" : "./", + } +} + diff --git a/doc/examples/cpufreq_governor_efficiency/calibration.sh b/doc/examples/cpufreq_governor_efficiency/calibration.sh new file mode 100755 index 0000000..d10e644 --- /dev/null +++ b/doc/examples/cpufreq_governor_efficiency/calibration.sh @@ -0,0 +1,11 @@ +#!/bin/sh + +set -e + +echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor + +sleep 1 + +pLoad=$(rt-app calibration.json 2>&1 |grep pLoad |sed 's/.*= (.*)ns.*/\1/') +sed 's/"calibration" : .*,/"calibration" : '$pLoad',/' -i dvfs.json + diff --git a/doc/examples/cpufreq_governor_efficiency/dvfs.json b/doc/examples/cpufreq_governor_efficiency/dvfs.json new file mode 100644 index 0000000..b413156 --- /dev/null +++ b/doc/examples/cpufreq_governor_efficiency/dvfs.json @@ -0,0 +1,27 @@ +{ + "tasks" : { + "thread" : { + "instance" : 1, + "cpus" : [0], + "loop" : 5, + "phases" : { + "running" : { + "loop" : 1, + "run" : 100000, + }, + "sleeping" : { + "loop" : 1, + "sleep" : 1000000, + } + } + } + }, + "global" : { + "default_policy" : "SCHED_OTHER", + "calibration" : 90, + "lock_pages" : true, + "ftrace" : true, + "logdir" : "./", + } +} + diff --git a/doc/examples/cpufreq_governor_efficiency/dvfs.sh b/doc/examples/cpufreq_governor_efficiency/dvfs.sh new file mode 100755 index 0000000..8e09e36 --- /dev/null +++ b/doc/examples/cpufreq_governor_efficiency/dvfs.sh @@ -0,0 +1,38 @@ +#!/bin/sh + +#echo $1 $2 $3 +set -e + +if [ $1 ] && [ $2 ] ; then + for i in $(seq 0 1 $(expr $2 - 1)); do + echo $1 > /sys/devices/system/cpu/cpu$i/cpufreq/scaling_governor + #cat /sys/devices/system/cpu/cpu$i/cpufreq/scaling_governor + done + + sleep 3 +fi + +if [ $3 ] ; then + sed 's/"run" : .*,/"run" : '$3',/' -i dvfs.json +fi + +if [ $4 ] ; then + sed 's/"sleep" : .*,/"sleep" : '$4',/' -i dvfs.json +fi + +#cat dvfs.json + +rt-app dvfs.json 2> /dev/null + +if [ $1 ] ; then + mv rt-app-thread-0.log rt-app_$1_run$3us_sleep$4us.log + + sum=0 + for i in $(cat rt-app_$1_run$3us_sleep$4us.log | sed 'n;d' | sed '1d' |cut -f 3); do + sum=$(expr $sum + $i) + done + sum=$(expr $sum / 5) + echo $sum + rm -f rt-app_$1_run$3us_sleep$4us.log +fi + diff --git a/doc/examples/cpufreq_governor_efficiency/test.sh b/doc/examples/cpufreq_governor_efficiency/test.sh new file mode 100755 index 0000000..a378aa8 --- /dev/null +++ b/doc/examples/cpufreq_governor_efficiency/test.sh @@ -0,0 +1,82 @@ +#!/bin/sh + +set -e + +set_calibration() { + calibration.sh +} + +test_efficiency() { + + FILENAME="results_$RANDOM$$.txt" + + if [ -e /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors ]; then + for i in $(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors); do + export gov_$i=$(echo $i) + done + else + echo "cpufreq is not available!" + exit + fi + + if [ ! $gov_performance ] ; then + echo "Can't found performance governor!" + exit + fi + + if [ ! $gov_powersave ] ; then + echo "Can't found powersave governor!" + exit + fi + + # Get powersave data + dvfs.sh powersave $1 $2 $3 > $FILENAME + powersave=$(cat $FILENAME |sed -n '1p') + + # Get performance data + dvfs.sh performance $1 $2 $3 > $FILENAME + performance=$(cat $FILENAME |sed -n '1p') + + denominator=$(expr $powersave - $performance) + if [ $denominator -le 0 ] ; then + echo "Error! Probably not input all the cpus in the same frequncy domain" + exit + fi + + echo "powersave efficiency: 0%" + echo "performance efficiency: 100%" + + # Calcuate other governors data + for gov_next in $gov_conservative $gov_ondemand $gov_cfs; do + if [ "$gov_next" != "" ] ; then + dvfs.sh $gov_next $1 $2 $3 > $FILENAME + data=$(cat $FILENAME |sed -n '1p'); + numerator=$(expr $powersave - $data) + numerator=$(expr $numerator * 100) + if [ $numerator -lt 0 ] ; then + let numerator=0 + fi + data=$(expr $numerator / $denominator) + echo "$gov_next efficiency: $data%" + fi + done + + rm -f $FILENAME +} + +if [ $# -lt 3 ]; then + echo "Usage: ./test.sh <cpus> <runtime> <sleeptime>" + echo "cpus: number of cpus in the CPU0's frequency domain" + echo "runtime: running time in ms per loop of the workload pattern" + echo "sleeptime: sleeping time in ms per loop of the workload pattern" + echo -e "\nExample: \n"./test.sh 4 100 1000" means\nCPU0~CPU3 sharing frequency, "100ms run + 1000ms sleep" workload pattern.\n" + exit +fi + +echo "Frequency domain CPU0~CPU$(expr $1 - 1), run $2ms, sleep $3ms:" + +sleep 1 +PATH=$PATH:. +set_calibration +test_efficiency $1 $(expr $2 * 1000) $(expr $3 * 1000) +