The patch will fix the invalid desired perf value for powersave
governor. This issue is found when testing on one AMD EPYC system, the
actual des_perf is smaller than the min_perf value, that is invalid
value. because the min_perf is the lowest_perf system can support in
idle state.
Signed-off-by: Perry Yuan <[email protected]>
---
drivers/cpufreq/amd-pstate.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 7c51f4125263..154eed849f38 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -317,6 +317,7 @@ static int amd_pstate_target(struct cpufreq_policy *policy,
des_perf = DIV_ROUND_CLOSEST(target_freq * cap_perf,
cpudata->max_freq);
+ des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
cpufreq_freq_transition_begin(policy, &freqs);
amd_pstate_update(cpudata, min_perf, des_perf,
max_perf, false);
--
2.25.1
On 7/7/22 12:00, Perry Yuan wrote:
> The patch will fix the invalid desired perf value for powersave
> governor. This issue is found when testing on one AMD EPYC system, the
> actual des_perf is smaller than the min_perf value, that is invalid
> value. because the min_perf is the lowest_perf system can support in
> idle state.
>
> Signed-off-by: Perry Yuan <[email protected]>
> ---
> drivers/cpufreq/amd-pstate.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 7c51f4125263..154eed849f38 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -317,6 +317,7 @@ static int amd_pstate_target(struct cpufreq_policy *policy,
> des_perf = DIV_ROUND_CLOSEST(target_freq * cap_perf,
> cpudata->max_freq);
>
> + des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
> cpufreq_freq_transition_begin(policy, &freqs);
> amd_pstate_update(cpudata, min_perf, des_perf,
> max_perf, false);
The clamping of the desired perf value should be moved to amd_pstate_update(). The
only other caller of amd_pstate_update() is amd_pstate_adjust_perf() which already
clamps the desired perf value before making the call.
-Nathan
[AMD Official Use Only - General]
Hi Nathan:
> -----Original Message-----
> From: Fontenot, Nathan <[email protected]>
> Sent: Friday, July 8, 2022 3:57 AM
> To: Yuan, Perry <[email protected]>; [email protected];
> [email protected]; Huang, Ray <[email protected]>; Rafael J.
> Wysocki <[email protected]>; [email protected]; linux-
> [email protected]
> Cc: Sharma, Deepak <[email protected]>; Limonciello, Mario
> <[email protected]>; Fontenot, Nathan
> <[email protected]>; Deucher, Alexander
> <[email protected]>; Su, Jinzhou (Joe) <[email protected]>;
> Huang, Shimmer <[email protected]>; Du, Xiaojian
> <[email protected]>; Meng, Li (Jassmine) <[email protected]>
> Subject: Re: [PATCH 07/12] cpufreq: amd_pstate: map desired perf into
> pstate scope for powersave governor
>
> On 7/7/22 12:00, Perry Yuan wrote:
> > The patch will fix the invalid desired perf value for powersave
> > governor. This issue is found when testing on one AMD EPYC system, the
> > actual des_perf is smaller than the min_perf value, that is invalid
> > value. because the min_perf is the lowest_perf system can support in
> > idle state.
> >
> > Signed-off-by: Perry Yuan <[email protected]>
> > ---
> > drivers/cpufreq/amd-pstate.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/cpufreq/amd-pstate.c
> > b/drivers/cpufreq/amd-pstate.c index 7c51f4125263..154eed849f38
> 100644
> > --- a/drivers/cpufreq/amd-pstate.c
> > +++ b/drivers/cpufreq/amd-pstate.c
> > @@ -317,6 +317,7 @@ static int amd_pstate_target(struct cpufreq_policy
> *policy,
> > des_perf = DIV_ROUND_CLOSEST(target_freq * cap_perf,
> > cpudata->max_freq);
> >
> > + des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
> > cpufreq_freq_transition_begin(policy, &freqs);
> > amd_pstate_update(cpudata, min_perf, des_perf,
> > max_perf, false);
>
> The clamping of the desired perf value should be moved to
> amd_pstate_update(). The only other caller of amd_pstate_update() is
> amd_pstate_adjust_perf() which already clamps the desired perf value
> before making the call.
>
> -Nathan
Thanks for your suggestion.
Add this change into V2.
Perry.