RE: [PATCH v3 3/5] cpupower: Add EPP value change support

[Yuan, Perry]

[AMD Official Use Only - General]

> -----Original Message-----
> From: Karny, Wyes <Wyes.Karny@xxxxxxx>
> Sent: Tuesday, June 20, 2023 3:05 AM
> To: trenn@xxxxxxxx; shuah@xxxxxxxxxx
> Cc: linux-pm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; rafael@xxxxxxxxxx;
> Shenoy, Gautham Ranjal <gautham.shenoy@xxxxxxx>; Limonciello, Mario
> <Mario.Limonciello@xxxxxxx>; Huang, Ray <Ray.Huang@xxxxxxx>; Yuan,
> Perry <Perry.Yuan@xxxxxxx>; Karny, Wyes <Wyes.Karny@xxxxxxx>;
> Limonciello, Mario <Mario.Limonciello@xxxxxxx>
> Subject: [PATCH v3 3/5] cpupower: Add EPP value change support
>
> amd_pstate and intel_pstate active mode drivers support energy performance
> preference feature. Through this user can convey it's energy/performance
> preference to platform. Add this value change capability to cpupower.
>
> To change the EPP value use below command:
> cpupower set --epp performance
>
> Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> Signed-off-by: Wyes Karny <wyes.karny@xxxxxxx>
> ---
>  tools/power/cpupower/utils/cpupower-set.c    | 23 +++++++++++++++++++-
>  tools/power/cpupower/utils/helpers/helpers.h |  5 +++++
>  tools/power/cpupower/utils/helpers/misc.c    | 19 ++++++++++++++++
>  3 files changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/tools/power/cpupower/utils/cpupower-set.c
> b/tools/power/cpupower/utils/cpupower-set.c
> index 180d5ba877e6..a789b123dbd4 100644
> --- a/tools/power/cpupower/utils/cpupower-set.c
> +++ b/tools/power/cpupower/utils/cpupower-set.c
> @@ -18,6 +18,7 @@
>
>  static struct option set_opts[] = {
>       {"perf-bias", required_argument, NULL, 'b'},
> +     {"epp", required_argument, NULL, 'e'},
>       { },
>  };
>
> @@ -37,11 +38,13 @@ int cmd_set(int argc, char **argv)
>       union {
>               struct {
>                       int perf_bias:1;
> +                     int epp:1;
>               };
>               int params;
>       } params;
>       int perf_bias = 0;
>       int ret = 0;
> +     char epp[30];
>
>       ret = uname(&uts);
>       if (!ret && (!strcmp(uts.machine, "ppc64le") || @@ -55,7 +58,7 @@
> int cmd_set(int argc, char **argv)
>
>       params.params = 0;
>       /* parameter parsing */
> -     while ((ret = getopt_long(argc, argv, "b:",
> +     while ((ret = getopt_long(argc, argv, "b:e:",
>                                               set_opts, NULL)) != -1) {
>               switch (ret) {
>               case 'b':
> @@ -69,6 +72,15 @@ int cmd_set(int argc, char **argv)
>                       }
>                       params.perf_bias = 1;
>                       break;
> +             case 'e':
> +                     if (params.epp)
> +                             print_wrong_arg_exit();
> +                     if (sscanf(optarg, "%29s", epp) != 1) {
> +                             print_wrong_arg_exit();
> +                             return -EINVAL;
> +                     }
> +                     params.epp = 1;
> +                     break;
>               default:
>                       print_wrong_arg_exit();
>               }
> @@ -102,6 +114,15 @@ int cmd_set(int argc, char **argv)
>                               break;
>                       }
>               }
> +
> +             if (params.epp) {
> +                     ret = cpupower_set_epp(cpu, epp);
> +                     if (ret) {
> +                             fprintf(stderr,
> +                                     "Error setting epp value on
> CPU %d\n", cpu);
> +                             break;
> +                     }
> +             }
>       }
>       return ret;
>  }
> diff --git a/tools/power/cpupower/utils/helpers/helpers.h
> b/tools/power/cpupower/utils/helpers/helpers.h
> index 96e4bede078b..5d998de2d291 100644
> --- a/tools/power/cpupower/utils/helpers/helpers.h
> +++ b/tools/power/cpupower/utils/helpers/helpers.h
> @@ -116,6 +116,8 @@ extern int cpupower_intel_set_perf_bias(unsigned int
> cpu, unsigned int val);  extern int cpupower_intel_get_perf_bias(unsigned int
> cpu);  extern unsigned long long msr_intel_get_turbo_ratio(unsigned int cpu);
>
> +extern int cpupower_set_epp(unsigned int cpu, char *epp);
> +
>  /* Read/Write msr ****************************/
>
>  /* PCI stuff ****************************/ @@ -173,6 +175,9 @@ static
> inline int cpupower_intel_get_perf_bias(unsigned int cpu)  static inline
> unsigned long long msr_intel_get_turbo_ratio(unsigned int cpu)  { return 0; };
>
> +static inline int cpupower_set_epp(unsigned int cpu, char *epp) {
> +return -1; };
> +
>  /* Read/Write msr ****************************/
>
>  static inline int cpufreq_has_boost_support(unsigned int cpu, int *support, diff
> --git a/tools/power/cpupower/utils/helpers/misc.c
> b/tools/power/cpupower/utils/helpers/misc.c
> index 0c56fc77f93b..583df38ab13c 100644
> --- a/tools/power/cpupower/utils/helpers/misc.c
> +++ b/tools/power/cpupower/utils/helpers/misc.c
> @@ -87,6 +87,25 @@ int cpupower_intel_set_perf_bias(unsigned int cpu,
> unsigned int val)
>       return 0;
>  }
>
> +int cpupower_set_epp(unsigned int cpu, char *epp) {
> +     char path[SYSFS_PATH_MAX];
> +     char linebuf[30] = {};
> +
> +     snprintf(path, sizeof(path),
> +             PATH_TO_CPU
> "cpu%u/cpufreq/energy_performance_preference", cpu);
> +
> +     if (!is_valid_path(path))
> +             return -1;
> +
> +     snprintf(linebuf, sizeof(linebuf), "%s", epp);
> +
> +     if (cpupower_write_sysfs(path, linebuf, 30) <= 0)
> +             return -1;
> +
> +     return 0;
> +}
> +
>  bool cpupower_amd_pstate_enabled(void)
>  {
>       char *driver = cpufreq_get_driver(0);
> --
> 2.34.1

Tested-by: Perry Yuan <Perry.Yuan@xxxxxxx>