* [PATCH] kselftest: cpufreq: Backup and restore governor for sptests
@ 2026-07-06 16:14 Yiwei Lin
2026-07-07 5:19 ` Viresh Kumar
0 siblings, 1 reply; 2+ messages in thread
From: Yiwei Lin @ 2026-07-06 16:14 UTC (permalink / raw)
To: rafael, viresh.kumar, shuah
Cc: linux-pm, linux-kselftest, linux-kernel, Yiwei Lin
After executing cpufreq sptest, the system governor
will be overwritten with the governor switched
during the test. Restore this setting to maintain
consistency before and after the test.
Signed-off-by: Yiwei Lin <s921975628@gmail.com>
---
tools/testing/selftests/cpufreq/governor.sh | 21 +++++++++++++++++++
.../selftests/cpufreq/special-tests.sh | 13 ++++++++++++
2 files changed, 34 insertions(+)
diff --git a/tools/testing/selftests/cpufreq/governor.sh b/tools/testing/selftests/cpufreq/governor.sh
index fe37df79c0871..5d105ab9c9222 100755
--- a/tools/testing/selftests/cpufreq/governor.sh
+++ b/tools/testing/selftests/cpufreq/governor.sh
@@ -16,6 +16,12 @@ source cpufreq.sh
CUR_GOV=
CUR_FREQ=
+# Per-policy backup, keyed by policy so multiple policies can be saved at once
+# (backup_governor/restore_governor also keep CUR_GOV/CUR_FREQ for callers that
+# read them directly).
+declare -A SAVED_GOVERNORS
+declare -A SAVED_FREQS
+
# Find governor's directory path
# $1: policy, $2: governor
find_gov_directory()
@@ -39,11 +45,13 @@ find_current_governor()
backup_governor()
{
CUR_GOV=$(find_current_governor $1)
+ SAVED_GOVERNORS[$1]=$CUR_GOV
printf "Governor backup done for $1: $CUR_GOV\n"
if [ $CUR_GOV == "userspace" ]; then
CUR_FREQ=$(find_current_freq $1)
+ SAVED_FREQS[$1]=$CUR_FREQ
printf "Governor frequency backup done for $1: $CUR_FREQ\n"
fi
@@ -53,11 +61,13 @@ backup_governor()
# $1: policy
restore_governor()
{
+ CUR_GOV=${SAVED_GOVERNORS[$1]}
__switch_governor $1 $CUR_GOV
printf "Governor restored for $1 to $CUR_GOV\n"
if [ $CUR_GOV == "userspace" ]; then
+ CUR_FREQ=${SAVED_FREQS[$1]}
set_cpu_frequency $1 $CUR_FREQ
printf "Governor frequency restored for $1: $CUR_FREQ\n"
fi
@@ -65,6 +75,17 @@ restore_governor()
printf "\n"
}
+# Save/restore governors for every policy at once
+save_all_governors()
+{
+ for_each_policy backup_governor
+}
+
+restore_all_governors()
+{
+ for_each_policy restore_governor
+}
+
# param:
# $1: policy, $2: governor
__switch_governor()
diff --git a/tools/testing/selftests/cpufreq/special-tests.sh b/tools/testing/selftests/cpufreq/special-tests.sh
index 8d40505dc4682..c7eddadd047d1 100755
--- a/tools/testing/selftests/cpufreq/special-tests.sh
+++ b/tools/testing/selftests/cpufreq/special-tests.sh
@@ -40,7 +40,9 @@ simple_lockdep()
{
printf "** Test: Running ${FUNCNAME[0]} **\n"
+ save_all_governors
for_each_policy __simple_lockdep
+ restore_all_governors
}
# Test 2
@@ -56,7 +58,10 @@ concurrent_lockdep()
{
printf "** Test: Running ${FUNCNAME[0]} **\n"
+ save_all_governors
for_each_policy_concurrent __concurrent_lockdep
+ wait
+ restore_all_governors
}
# Test 3
@@ -68,17 +73,23 @@ quick_shuffle()
echo ondemand | sudo tee $CPUFREQROOT/policy*/scaling_governor &
echo userspace | sudo tee $CPUFREQROOT/policy*/scaling_governor &
done
+ wait
}
governor_race()
{
printf "** Test: Running ${FUNCNAME[0]} **\n"
+ save_all_governors
+
# run 8 concurrent instances
for I in `seq 8`
do
quick_shuffle &
done
+ wait
+
+ restore_all_governors
}
# Test 4
@@ -112,5 +123,7 @@ hotplug_with_updates_cpu()
hotplug_with_updates()
{
+ save_all_governors
for_each_non_boot_cpu hotplug_with_updates_cpu
+ restore_all_governors
}
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] kselftest: cpufreq: Backup and restore governor for sptests
2026-07-06 16:14 [PATCH] kselftest: cpufreq: Backup and restore governor for sptests Yiwei Lin
@ 2026-07-07 5:19 ` Viresh Kumar
0 siblings, 0 replies; 2+ messages in thread
From: Viresh Kumar @ 2026-07-07 5:19 UTC (permalink / raw)
To: Yiwei Lin; +Cc: rafael, shuah, linux-pm, linux-kselftest, linux-kernel
On 07-07-26, 00:14, Yiwei Lin wrote:
> After executing cpufreq sptest, the system governor
> will be overwritten with the governor switched
> during the test. Restore this setting to maintain
> consistency before and after the test.
>
> Signed-off-by: Yiwei Lin <s921975628@gmail.com>
> ---
> tools/testing/selftests/cpufreq/governor.sh | 21 +++++++++++++++++++
> .../selftests/cpufreq/special-tests.sh | 13 ++++++++++++
> 2 files changed, 34 insertions(+)
>
> diff --git a/tools/testing/selftests/cpufreq/governor.sh b/tools/testing/selftests/cpufreq/governor.sh
> index fe37df79c0871..5d105ab9c9222 100755
> --- a/tools/testing/selftests/cpufreq/governor.sh
> +++ b/tools/testing/selftests/cpufreq/governor.sh
> @@ -16,6 +16,12 @@ source cpufreq.sh
> CUR_GOV=
> CUR_FREQ=
>
> +# Per-policy backup, keyed by policy so multiple policies can be saved at once
> +# (backup_governor/restore_governor also keep CUR_GOV/CUR_FREQ for callers that
> +# read them directly).
> +declare -A SAVED_GOVERNORS
> +declare -A SAVED_FREQS
> +
> # Find governor's directory path
> # $1: policy, $2: governor
> find_gov_directory()
> @@ -39,11 +45,13 @@ find_current_governor()
> backup_governor()
> {
> CUR_GOV=$(find_current_governor $1)
> + SAVED_GOVERNORS[$1]=$CUR_GOV
>
> printf "Governor backup done for $1: $CUR_GOV\n"
>
> if [ $CUR_GOV == "userspace" ]; then
> CUR_FREQ=$(find_current_freq $1)
> + SAVED_FREQS[$1]=$CUR_FREQ
> printf "Governor frequency backup done for $1: $CUR_FREQ\n"
> fi
>
> @@ -53,11 +61,13 @@ backup_governor()
> # $1: policy
> restore_governor()
> {
> + CUR_GOV=${SAVED_GOVERNORS[$1]}
> __switch_governor $1 $CUR_GOV
>
> printf "Governor restored for $1 to $CUR_GOV\n"
>
> if [ $CUR_GOV == "userspace" ]; then
> + CUR_FREQ=${SAVED_FREQS[$1]}
> set_cpu_frequency $1 $CUR_FREQ
> printf "Governor frequency restored for $1: $CUR_FREQ\n"
> fi
> @@ -65,6 +75,17 @@ restore_governor()
> printf "\n"
> }
>
> +# Save/restore governors for every policy at once
> +save_all_governors()
> +{
> + for_each_policy backup_governor
> +}
> +
> +restore_all_governors()
> +{
> + for_each_policy restore_governor
> +}
> +
> # param:
> # $1: policy, $2: governor
> __switch_governor()
> diff --git a/tools/testing/selftests/cpufreq/special-tests.sh b/tools/testing/selftests/cpufreq/special-tests.sh
> index 8d40505dc4682..c7eddadd047d1 100755
> --- a/tools/testing/selftests/cpufreq/special-tests.sh
> +++ b/tools/testing/selftests/cpufreq/special-tests.sh
> @@ -40,7 +40,9 @@ simple_lockdep()
> {
> printf "** Test: Running ${FUNCNAME[0]} **\n"
>
> + save_all_governors
> for_each_policy __simple_lockdep
> + restore_all_governors
> }
>
> # Test 2
> @@ -56,7 +58,10 @@ concurrent_lockdep()
> {
> printf "** Test: Running ${FUNCNAME[0]} **\n"
>
> + save_all_governors
> for_each_policy_concurrent __concurrent_lockdep
> + wait
> + restore_all_governors
> }
>
> # Test 3
> @@ -68,17 +73,23 @@ quick_shuffle()
> echo ondemand | sudo tee $CPUFREQROOT/policy*/scaling_governor &
> echo userspace | sudo tee $CPUFREQROOT/policy*/scaling_governor &
> done
> + wait
> }
>
> governor_race()
> {
> printf "** Test: Running ${FUNCNAME[0]} **\n"
>
> + save_all_governors
> +
> # run 8 concurrent instances
> for I in `seq 8`
> do
> quick_shuffle &
> done
> + wait
> +
> + restore_all_governors
> }
>
> # Test 4
> @@ -112,5 +123,7 @@ hotplug_with_updates_cpu()
>
> hotplug_with_updates()
> {
> + save_all_governors
> for_each_non_boot_cpu hotplug_with_updates_cpu
Don't you need wait here too ?
> + restore_all_governors
> }
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
--
viresh
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