Currently the the config fragment for cpufreq enables a lot of generic lock debugging. While these options are useful when testing cpufreq they aren't actually required to run the tests and are therefore out of scope for the cpufreq fragement, they are more of a thing that it's good to enable while doing testing than an actual requirement for cpufreq testing specifically. Having these debugging options enabled, especially the mutex and spinlock instrumentation, mean that any build that includes the cpufreq fragment is both very much larger than a standard defconfig (eg, I'm seeing 35% on x86_64) and also slower at runtime.
This is causing real problems for CI systems. In order to avoid building large numbers of kernels they try to group kselftest fragments together, frequently just grouping all the kselftest fragments into a single block. The increased size is an issue for memory constrained systems and is also problematic for systems with fixed storage allocations for kernel images (eg, typical u-boot systems) where it frequently causes the kernel to overflow the storage space allocated for kernels. The reduced performance isn't too bad with real hardware but can be disruptive on emulated platforms.
In order to avoid these issues remove these generic instrumentation options from the cpufreq fragment, bringing the cpufreq fragment into line with other fragments which generally set requirements for testing rather than nice to haves.
Signed-off-by: Mark Brown broonie@kernel.org --- tools/testing/selftests/cpufreq/config | 8 -------- 1 file changed, 8 deletions(-)
diff --git a/tools/testing/selftests/cpufreq/config b/tools/testing/selftests/cpufreq/config index 75e900793e8a..ce5068f5a6a2 100644 --- a/tools/testing/selftests/cpufreq/config +++ b/tools/testing/selftests/cpufreq/config @@ -5,11 +5,3 @@ CONFIG_CPU_FREQ_GOV_USERSPACE=y CONFIG_CPU_FREQ_GOV_ONDEMAND=y CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y CONFIG_CPU_FREQ_GOV_SCHEDUTIL=y -CONFIG_DEBUG_RT_MUTEXES=y -CONFIG_DEBUG_PLIST=y -CONFIG_DEBUG_SPINLOCK=y -CONFIG_DEBUG_MUTEXES=y -CONFIG_DEBUG_LOCK_ALLOC=y -CONFIG_PROVE_LOCKING=y -CONFIG_LOCKDEP=y -CONFIG_DEBUG_ATOMIC_SLEEP=y
--- base-commit: ac9a78681b921877518763ba0e89202254349d1b change-id: 20230605-kselftest-cpufreq-options-2fd6d4742333
Best regards,
On 06-06-23, 15:11, Mark Brown wrote:
Currently the the config fragment for cpufreq enables a lot of generic lock debugging. While these options are useful when testing cpufreq they aren't actually required to run the tests and are therefore out of scope for the cpufreq fragement, they are more of a thing that it's good to enable while doing testing than an actual requirement for cpufreq testing specifically. Having these debugging options enabled, especially the mutex and spinlock instrumentation, mean that any build that includes the cpufreq fragment is both very much larger than a standard defconfig (eg, I'm seeing 35% on x86_64) and also slower at runtime.
This is causing real problems for CI systems. In order to avoid building large numbers of kernels they try to group kselftest fragments together, frequently just grouping all the kselftest fragments into a single block. The increased size is an issue for memory constrained systems and is also problematic for systems with fixed storage allocations for kernel images (eg, typical u-boot systems) where it frequently causes the kernel to overflow the storage space allocated for kernels. The reduced performance isn't too bad with real hardware but can be disruptive on emulated platforms.
In order to avoid these issues remove these generic instrumentation options from the cpufreq fragment, bringing the cpufreq fragment into line with other fragments which generally set requirements for testing rather than nice to haves.
Acked-by: Viresh Kumar viresh.kumar@linaro.org
Signed-off-by: Mark Brown broonie@kernel.org
tools/testing/selftests/cpufreq/config | 8 -------- 1 file changed, 8 deletions(-)
diff --git a/tools/testing/selftests/cpufreq/config b/tools/testing/selftests/cpufreq/config index 75e900793e8a..ce5068f5a6a2 100644 --- a/tools/testing/selftests/cpufreq/config +++ b/tools/testing/selftests/cpufreq/config @@ -5,11 +5,3 @@ CONFIG_CPU_FREQ_GOV_USERSPACE=y CONFIG_CPU_FREQ_GOV_ONDEMAND=y CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y CONFIG_CPU_FREQ_GOV_SCHEDUTIL=y -CONFIG_DEBUG_RT_MUTEXES=y -CONFIG_DEBUG_PLIST=y -CONFIG_DEBUG_SPINLOCK=y -CONFIG_DEBUG_MUTEXES=y -CONFIG_DEBUG_LOCK_ALLOC=y -CONFIG_PROVE_LOCKING=y -CONFIG_LOCKDEP=y -CONFIG_DEBUG_ATOMIC_SLEEP=y
FWIW, I enabled these earlier as cpufreq core had a history of races that are normally not caught without these enabled. But I think we have come a long way from that and these can be removed now.
On 6/6/23 21:45, Viresh Kumar wrote:
On 06-06-23, 15:11, Mark Brown wrote:
Currently the the config fragment for cpufreq enables a lot of generic lock debugging. While these options are useful when testing cpufreq they aren't actually required to run the tests and are therefore out of scope for the cpufreq fragement, they are more of a thing that it's good to enable while doing testing than an actual requirement for cpufreq testing specifically. Having these debugging options enabled, especially the mutex and spinlock instrumentation, mean that any build that includes the cpufreq fragment is both very much larger than a standard defconfig (eg, I'm seeing 35% on x86_64) and also slower at runtime.
This is causing real problems for CI systems. In order to avoid building large numbers of kernels they try to group kselftest fragments together, frequently just grouping all the kselftest fragments into a single block. The increased size is an issue for memory constrained systems and is also problematic for systems with fixed storage allocations for kernel images (eg, typical u-boot systems) where it frequently causes the kernel to overflow the storage space allocated for kernels. The reduced performance isn't too bad with real hardware but can be disruptive on emulated platforms.
In order to avoid these issues remove these generic instrumentation options from the cpufreq fragment, bringing the cpufreq fragment into line with other fragments which generally set requirements for testing rather than nice to haves.
Acked-by: Viresh Kumar viresh.kumar@linaro.org
Signed-off-by: Mark Brown broonie@kernel.org
tools/testing/selftests/cpufreq/config | 8 -------- 1 file changed, 8 deletions(-)
diff --git a/tools/testing/selftests/cpufreq/config b/tools/testing/selftests/cpufreq/config index 75e900793e8a..ce5068f5a6a2 100644 --- a/tools/testing/selftests/cpufreq/config +++ b/tools/testing/selftests/cpufreq/config @@ -5,11 +5,3 @@ CONFIG_CPU_FREQ_GOV_USERSPACE=y CONFIG_CPU_FREQ_GOV_ONDEMAND=y CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y CONFIG_CPU_FREQ_GOV_SCHEDUTIL=y -CONFIG_DEBUG_RT_MUTEXES=y -CONFIG_DEBUG_PLIST=y -CONFIG_DEBUG_SPINLOCK=y -CONFIG_DEBUG_MUTEXES=y -CONFIG_DEBUG_LOCK_ALLOC=y -CONFIG_PROVE_LOCKING=y -CONFIG_LOCKDEP=y -CONFIG_DEBUG_ATOMIC_SLEEP=y
FWIW, I enabled these earlier as cpufreq core had a history of races that are normally not caught without these enabled. But I think we have come a long way from that and these can be removed now.
Thank you both. Applied to linux-kselftest next for Linux 6.5-rc1 This gives us time to ensure the above mentioned races are no longer an issue.
thanks, -- Shuah
linux-kselftest-mirror@lists.linaro.org
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Mark Brown -
Shuah Khan -
Viresh Kumar