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..8a2b6ad9b8c0 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -265,6 +265,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
u64 prev = READ_ONCE(cpudata->cppc_req_cached);
u64 value = prev;
+ des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
value &= ~AMD_CPPC_MIN_PERF(~0L);
value |= AMD_CPPC_MIN_PERF(min_perf);
--
2.25.1
On 7/9/22 09:19, 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..8a2b6ad9b8c0 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -265,6 +265,7 @@ static void amd_pstate_update(struct amd_cpudata *cpudata, u32 min_perf,
> u64 prev = READ_ONCE(cpudata->cppc_req_cached);
> u64 value = prev;
>
> + des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
You should also update amd_pstate_adjust_perf() to remove the clamp_t() call now
that it is done here.
-Nathan
> value &= ~AMD_CPPC_MIN_PERF(~0L);
> value |= AMD_CPPC_MIN_PERF(min_perf);
>
[AMD Official Use Only - General]
Hi Nathan.
> -----Original Message-----
> From: Fontenot, Nathan <[email protected]>
> Sent: Tuesday, July 12, 2022 3:34 AM
> To: Yuan, Perry <[email protected]>; [email protected];
> [email protected]; Huang, Ray <[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]>; linux-
> [email protected]; [email protected]
> Subject: Re: [PATCH v2 07/14] cpufreq: amd_pstate: map desired perf into
> pstate scope for powersave governor
>
> On 7/9/22 09:19, 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..8a2b6ad9b8c0
> 100644
> > --- a/drivers/cpufreq/amd-pstate.c
> > +++ b/drivers/cpufreq/amd-pstate.c
> > @@ -265,6 +265,7 @@ static void amd_pstate_update(struct
> amd_cpudata *cpudata, u32 min_perf,
> > u64 prev = READ_ONCE(cpudata->cppc_req_cached);
> > u64 value = prev;
> >
> > + des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
>
> You should also update amd_pstate_adjust_perf() to remove the clamp_t()
> call now that it is done here.
>
> -Nathan
I missed that, changed into V3.
Thank you!
Perry.
>
> > value &= ~AMD_CPPC_MIN_PERF(~0L);
> > value |= AMD_CPPC_MIN_PERF(min_perf);
> >