linux-kernel - Re: [PATCH v3 3/5] cpupower: Add EPP value change support

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Date:   Tue, 20 Jun 2023 20:59:46 +0800
From:   Huang Rui <ray.huang@....com>
To:     "Karny, Wyes" <Wyes.Karny@....com>
Cc:     "trenn@...e.com" <trenn@...e.com>,
        "shuah@...nel.org" <shuah@...nel.org>,
        "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "rafael@...nel.org" <rafael@...nel.org>,
        "Shenoy, Gautham Ranjal" <gautham.shenoy@....com>,
        "Limonciello, Mario" <Mario.Limonciello@....com>,
        "Yuan, Perry" <Perry.Yuan@....com>
Subject: Re: [PATCH v3 3/5] cpupower: Add EPP value change support

On Tue, Jun 20, 2023 at 03:05:01AM +0800, Karny, Wyes wrote:
> 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@....com>
> Signed-off-by: Wyes Karny <wyes.karny@....com>

Acked-by: Huang Rui <ray.huang@....com>

> ---
>  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
>