2014-10-15 23:18:03

by Pali Rohár

Subject: [PATCH] cpufreq: intel_pstate: Fix setting max_perf_pct in performance policy

Code which changes policy to powersave changes also max_policy_pct based on
max_freq. Code which change max_perf_pct has upper limit base on value
max_policy_pct. When policy is changing from powersave back to performance
then max_policy_pct is not changed. Which means that changing max_perf_pct is
not possible to high values if max_freq was too low in powersave policy.

Test case:

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
800000
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
3300000
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
100

$ echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
$ echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
$ echo 20 > /sys/devices/system/cpu/intel_pstate/max_perf_pct

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
powersave
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
800000
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
20

$ echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
$ echo 3300000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
$ echo 100 > /sys/devices/system/cpu/intel_pstate/max_perf_pct

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
3300000
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
24

And now intel_pstate driver allows to set maximal value for max_perf_pct based
on max_policy_pct which is 24 for previous powersave max_freq 800000.

This patch will set default value for max_policy_pct when setting policy to
performance so it will allow to set also max value for max_perf_pct.

Signed-off-by: Pali Rohár <[email protected]>
Cc: [email protected]
---
drivers/cpufreq/intel_pstate.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 0668b38..7547ab5 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -714,6 +714,7 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
limits.min_perf_pct = 100;
limits.min_perf = int_tofp(1);
+ limits.max_policy_pct = 100;
limits.max_perf_pct = 100;
limits.max_perf = int_tofp(1);
limits.no_turbo = limits.turbo_disabled;
--
1.7.9.5

2014-10-16 08:17:22

by Viresh Kumar

Subject: Re: [PATCH] cpufreq: intel_pstate: Fix setting max_perf_pct in performance policy

Cc'ing Dirk.

On 16 October 2014 04:46, Pali Rohár <[email protected]> wrote:
> Code which changes policy to powersave changes also max_policy_pct based on
> max_freq. Code which change max_perf_pct has upper limit base on value
> max_policy_pct. When policy is changing from powersave back to performance
> then max_policy_pct is not changed. Which means that changing max_perf_pct is
> not possible to high values if max_freq was too low in powersave policy.
>
> Test case:
>
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
> 800000
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> 3300000
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> performance
> $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> 100
>
> $ echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> $ echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> $ echo 20 > /sys/devices/system/cpu/intel_pstate/max_perf_pct
>
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> powersave
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> 800000
> $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> 20
>
> $ echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> $ echo 3300000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> $ echo 100 > /sys/devices/system/cpu/intel_pstate/max_perf_pct
>
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> performance
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> 3300000
> $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> 24
>
> And now intel_pstate driver allows to set maximal value for max_perf_pct based
> on max_policy_pct which is 24 for previous powersave max_freq 800000.
>
> This patch will set default value for max_policy_pct when setting policy to
> performance so it will allow to set also max value for max_perf_pct.
>
> Signed-off-by: Pali Rohár <[email protected]>
> Cc: [email protected]
> ---
> drivers/cpufreq/intel_pstate.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 0668b38..7547ab5 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -714,6 +714,7 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
> if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
> limits.min_perf_pct = 100;
> limits.min_perf = int_tofp(1);
> + limits.max_policy_pct = 100;
> limits.max_perf_pct = 100;
> limits.max_perf = int_tofp(1);
> limits.no_turbo = limits.turbo_disabled;
> --
> 1.7.9.5
>

2014-10-16 08:30:22

by Rafael J. Wysocki

Subject: Re: [PATCH] cpufreq: intel_pstate: Fix setting max_perf_pct in performance policy

On Thursday, October 16, 2014 01:16:51 AM Pali Rohár wrote:
> Code which changes policy to powersave changes also max_policy_pct based on
> max_freq. Code which change max_perf_pct has upper limit base on value
> max_policy_pct. When policy is changing from powersave back to performance
> then max_policy_pct is not changed. Which means that changing max_perf_pct is
> not possible to high values if max_freq was too low in powersave policy.

Dirk, what do you think?

> Test case:
>
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
> 800000
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> 3300000
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> performance
> $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> 100
>
> $ echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> $ echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> $ echo 20 > /sys/devices/system/cpu/intel_pstate/max_perf_pct
>
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> powersave
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> 800000
> $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> 20
>
> $ echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> $ echo 3300000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> $ echo 100 > /sys/devices/system/cpu/intel_pstate/max_perf_pct
>
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> performance
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> 3300000
> $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> 24
>
> And now intel_pstate driver allows to set maximal value for max_perf_pct based
> on max_policy_pct which is 24 for previous powersave max_freq 800000.
>
> This patch will set default value for max_policy_pct when setting policy to
> performance so it will allow to set also max value for max_perf_pct.
>
> Signed-off-by: Pali Rohár <[email protected]>
> Cc: [email protected]
> ---
> drivers/cpufreq/intel_pstate.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 0668b38..7547ab5 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -714,6 +714,7 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
> if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
> limits.min_perf_pct = 100;
> limits.min_perf = int_tofp(1);
> + limits.max_policy_pct = 100;
> limits.max_perf_pct = 100;
> limits.max_perf = int_tofp(1);
> limits.no_turbo = limits.turbo_disabled;
>

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

2014-10-16 15:05:43

by Dirk Brandewie

Subject: Re: [PATCH] cpufreq: intel_pstate: Fix setting max_perf_pct in performance policy

On 10/15/2014 04:16 PM, Pali Rohár wrote:
> Code which changes policy to powersave changes also max_policy_pct based on
> max_freq. Code which change max_perf_pct has upper limit base on value
> max_policy_pct. When policy is changing from powersave back to performance
> then max_policy_pct is not changed. Which means that changing max_perf_pct is
> not possible to high values if max_freq was too low in powersave policy.
>
> Test case:
>
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
> 800000
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> 3300000
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> performance
> $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> 100
>
> $ echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> $ echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> $ echo 20 > /sys/devices/system/cpu/intel_pstate/max_perf_pct
>
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> powersave
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> 800000
> $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> 20
>
> $ echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> $ echo 3300000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> $ echo 100 > /sys/devices/system/cpu/intel_pstate/max_perf_pct
>
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> performance
> $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> 3300000
> $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> 24
>
> And now intel_pstate driver allows to set maximal value for max_perf_pct based
> on max_policy_pct which is 24 for previous powersave max_freq 800000.
>
> This patch will set default value for max_policy_pct when setting policy to
> performance so it will allow to set also max value for max_perf_pct.
>
> Signed-off-by: Pali Rohár <[email protected]>

Acked-by: Dirk Brandewie <[email protected]>

> Cc: [email protected]
> ---
> drivers/cpufreq/intel_pstate.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 0668b38..7547ab5 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -714,6 +714,7 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
> if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) {
> limits.min_perf_pct = 100;
> limits.min_perf = int_tofp(1);
> + limits.max_policy_pct = 100;
> limits.max_perf_pct = 100;
> limits.max_perf = int_tofp(1);
> limits.no_turbo = limits.turbo_disabled;
>

2014-10-21 13:10:29

by Rafael J. Wysocki

Subject: Re: [PATCH] cpufreq: intel_pstate: Fix setting max_perf_pct in performance policy

On Thursday, October 16, 2014 08:05:44 AM Dirk Brandewie wrote:
> On 10/15/2014 04:16 PM, Pali Rohár wrote:
> > Code which changes policy to powersave changes also max_policy_pct based on
> > max_freq. Code which change max_perf_pct has upper limit base on value
> > max_policy_pct. When policy is changing from powersave back to performance
> > then max_policy_pct is not changed. Which means that changing max_perf_pct is
> > not possible to high values if max_freq was too low in powersave policy.
> >
> > Test case:
> >
> > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
> > 800000
> > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> > 3300000
> > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> > performance
> > $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> > 100
> >
> > $ echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> > $ echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> > $ echo 20 > /sys/devices/system/cpu/intel_pstate/max_perf_pct
> >
> > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> > powersave
> > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> > 800000
> > $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> > 20
> >
> > $ echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> > $ echo 3300000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> > $ echo 100 > /sys/devices/system/cpu/intel_pstate/max_perf_pct
> >
> > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> > performance
> > $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
> > 3300000
> > $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
> > 24
> >
> > And now intel_pstate driver allows to set maximal value for max_perf_pct based
> > on max_policy_pct which is 24 for previous powersave max_freq 800000.
> >
> > This patch will set default value for max_policy_pct when setting policy to
> > performance so it will allow to set also max value for max_perf_pct.
> >
> > Signed-off-by: Pali Rohár <[email protected]>
>
> Acked-by: Dirk Brandewie <[email protected]>

Applied, thanks!

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.