diff mbox series

cpufreq: amd-pstate: Update policy->cur for adjust perf

Message ID 20230518055819.71585-1-wyes.karny@amd.com
State New
Headers
Series cpufreq: amd-pstate: Update policy->cur for adjust perf |

Commit Message

Wyes Karny May 18, 2023, 5:58 a.m. UTC 
  Driver should update policy->cur after updating the frequency.
Currently amd_pstate doesn't update policy->cur when `adjust_perf`
is used. Which causes /proc/cpuinfo to show wrong cpu frequency.
Fix this by updating policy->cur with correct frequency value in
adjust_perf function callback.

- Before the fix: (setting min freq to 1.5 MHz)

[root@amd]# cat /proc/cpuinfo | grep "cpu MHz" | sort | uniq --count
      1 cpu MHz         : 1777.016
      1 cpu MHz         : 1797.160
      1 cpu MHz         : 1797.270
    189 cpu MHz         : 400.000

- After the fix: (setting min freq to 1.5 MHz)

[root@amd]# cat /proc/cpuinfo | grep "cpu MHz" | sort | uniq --count
      1 cpu MHz         : 1753.353
      1 cpu MHz         : 1756.838
      1 cpu MHz         : 1776.466
      1 cpu MHz         : 1776.873
      1 cpu MHz         : 1777.308
      1 cpu MHz         : 1779.900
    183 cpu MHz         : 1805.231
      1 cpu MHz         : 1956.815
      1 cpu MHz         : 2246.203
      1 cpu MHz         : 2259.984

Fixes: 1d215f0319c2 ("cpufreq: amd-pstate: Add fast switch function for AMD P-State")

Signed-off-by: Wyes Karny <wyes.karny@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

Comments

Rafael J. Wysocki May 24, 2023, 5:57 p.m. UTC | #1 
On Thu, May 18, 2023 at 7:58 AM Wyes Karny <wyes.karny@amd.com> wrote:
>
> Driver should update policy->cur after updating the frequency.
> Currently amd_pstate doesn't update policy->cur when `adjust_perf`
> is used. Which causes /proc/cpuinfo to show wrong cpu frequency.
> Fix this by updating policy->cur with correct frequency value in
> adjust_perf function callback.
>
> - Before the fix: (setting min freq to 1.5 MHz)
>
> [root@amd]# cat /proc/cpuinfo | grep "cpu MHz" | sort | uniq --count
>       1 cpu MHz         : 1777.016
>       1 cpu MHz         : 1797.160
>       1 cpu MHz         : 1797.270
>     189 cpu MHz         : 400.000
>
> - After the fix: (setting min freq to 1.5 MHz)
>
> [root@amd]# cat /proc/cpuinfo | grep "cpu MHz" | sort | uniq --count
>       1 cpu MHz         : 1753.353
>       1 cpu MHz         : 1756.838
>       1 cpu MHz         : 1776.466
>       1 cpu MHz         : 1776.873
>       1 cpu MHz         : 1777.308
>       1 cpu MHz         : 1779.900
>     183 cpu MHz         : 1805.231
>       1 cpu MHz         : 1956.815
>       1 cpu MHz         : 2246.203
>       1 cpu MHz         : 2259.984
>
> Fixes: 1d215f0319c2 ("cpufreq: amd-pstate: Add fast switch function for AMD P-State")
>
> Signed-off-by: Wyes Karny <wyes.karny@amd.com>
> ---
>  drivers/cpufreq/amd-pstate.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 5a3d4aa0f45a..736dab69ba1e 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -479,12 +479,14 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
>                                    unsigned long capacity)
>  {
>         unsigned long max_perf, min_perf, des_perf,
> -                     cap_perf, lowest_nonlinear_perf;
> +                     cap_perf, lowest_nonlinear_perf, max_freq;
>         struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
>         struct amd_cpudata *cpudata = policy->driver_data;
> +       unsigned int target_freq;
>
>         cap_perf = READ_ONCE(cpudata->highest_perf);
>         lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
> +       max_freq = READ_ONCE(cpudata->max_freq);
>
>         des_perf = cap_perf;
>         if (target_perf < capacity)
> @@ -501,6 +503,10 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
>         if (max_perf < min_perf)
>                 max_perf = min_perf;
>
> +       des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
> +       target_freq = div_u64(des_perf * max_freq, max_perf);
> +       policy->cur = target_freq;
> +
>         amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true,
>                         policy->governor->flags);
>         cpufreq_cpu_put(policy);
> --

Applied under an edited subject, thanks!

I think you'd like this to go into 6.4 and "stable", right?
Wyes Karny May 25, 2023, 6:13 a.m. UTC | #2 
Hi Rafael,

On 24 May 19:57, Rafael J. Wysocki wrote:
> On Thu, May 18, 2023 at 7:58 AM Wyes Karny <wyes.karny@amd.com> wrote:
> >
> > Driver should update policy->cur after updating the frequency.
> > Currently amd_pstate doesn't update policy->cur when `adjust_perf`
> > is used. Which causes /proc/cpuinfo to show wrong cpu frequency.
> > Fix this by updating policy->cur with correct frequency value in
> > adjust_perf function callback.
> >
> > - Before the fix: (setting min freq to 1.5 MHz)
> >
> > [root@amd]# cat /proc/cpuinfo | grep "cpu MHz" | sort | uniq --count
> >       1 cpu MHz         : 1777.016
> >       1 cpu MHz         : 1797.160
> >       1 cpu MHz         : 1797.270
> >     189 cpu MHz         : 400.000
> >
> > - After the fix: (setting min freq to 1.5 MHz)
> >
> > [root@amd]# cat /proc/cpuinfo | grep "cpu MHz" | sort | uniq --count
> >       1 cpu MHz         : 1753.353
> >       1 cpu MHz         : 1756.838
> >       1 cpu MHz         : 1776.466
> >       1 cpu MHz         : 1776.873
> >       1 cpu MHz         : 1777.308
> >       1 cpu MHz         : 1779.900
> >     183 cpu MHz         : 1805.231
> >       1 cpu MHz         : 1956.815
> >       1 cpu MHz         : 2246.203
> >       1 cpu MHz         : 2259.984
> >
> > Fixes: 1d215f0319c2 ("cpufreq: amd-pstate: Add fast switch function for AMD P-State")
> >
> > Signed-off-by: Wyes Karny <wyes.karny@amd.com>
> > ---
> >  drivers/cpufreq/amd-pstate.c | 8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> > index 5a3d4aa0f45a..736dab69ba1e 100644
> > --- a/drivers/cpufreq/amd-pstate.c
> > +++ b/drivers/cpufreq/amd-pstate.c
> > @@ -479,12 +479,14 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
> >                                    unsigned long capacity)
> >  {
> >         unsigned long max_perf, min_perf, des_perf,
> > -                     cap_perf, lowest_nonlinear_perf;
> > +                     cap_perf, lowest_nonlinear_perf, max_freq;
> >         struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
> >         struct amd_cpudata *cpudata = policy->driver_data;
> > +       unsigned int target_freq;
> >
> >         cap_perf = READ_ONCE(cpudata->highest_perf);
> >         lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
> > +       max_freq = READ_ONCE(cpudata->max_freq);
> >
> >         des_perf = cap_perf;
> >         if (target_perf < capacity)
> > @@ -501,6 +503,10 @@ static void amd_pstate_adjust_perf(unsigned int cpu,
> >         if (max_perf < min_perf)
> >                 max_perf = min_perf;
> >
> > +       des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
> > +       target_freq = div_u64(des_perf * max_freq, max_perf);
> > +       policy->cur = target_freq;
> > +
> >         amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true,
> >                         policy->governor->flags);
> >         cpufreq_cpu_put(policy);
> > --
> 
> Applied under an edited subject, thanks!
> 
> I think you'd like this to go into 6.4 and "stable", right?

Yes, please. I should have added stable tag.

Thanks & Regards,
Wyes
diff mbox series

Patch

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 5a3d4aa0f45a..736dab69ba1e 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -479,12 +479,14 @@  static void amd_pstate_adjust_perf(unsigned int cpu,
 				   unsigned long capacity)
 {
 	unsigned long max_perf, min_perf, des_perf,
-		      cap_perf, lowest_nonlinear_perf;
+		      cap_perf, lowest_nonlinear_perf, max_freq;
 	struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
 	struct amd_cpudata *cpudata = policy->driver_data;
+	unsigned int target_freq;
 
 	cap_perf = READ_ONCE(cpudata->highest_perf);
 	lowest_nonlinear_perf = READ_ONCE(cpudata->lowest_nonlinear_perf);
+	max_freq = READ_ONCE(cpudata->max_freq);
 
 	des_perf = cap_perf;
 	if (target_perf < capacity)
@@ -501,6 +503,10 @@  static void amd_pstate_adjust_perf(unsigned int cpu,
 	if (max_perf < min_perf)
 		max_perf = min_perf;
 
+	des_perf = clamp_t(unsigned long, des_perf, min_perf, max_perf);
+	target_freq = div_u64(des_perf * max_freq, max_perf);
+	policy->cur = target_freq;
+
 	amd_pstate_update(cpudata, min_perf, des_perf, max_perf, true,
 			policy->governor->flags);
 	cpufreq_cpu_put(policy);