| Message ID | 1441387159-19860-1-git-send-email-srinivas.pandruvada@linux.intel.com (mailing list archive) |
|---|---|
| State | RFC, archived |
| Headers | show |
On 04-09-15, 10:19, Srinivas Pandruvada wrote: > Currently scaling_available_frequencies displays list of available > frequencies which can be used to set max/min or current scaling > frequency. But because of configurable thermal design power implementation > in several Intel CPUs, this is not a guaranteed frequency or a P state, > which user can request. After a limit all frequencies (P states) may be > purely in opportunistic performance range. For example > > >cat scaling_available_frequencies > 2301000 2300000 2200000 2000000 1900000 1800000 1700000 1500000 1400000 > 1300000 1100000 1000000 900000 800000 600000 500000 > > Here traditionally it is assumed that only 2301000 is a turbo frequency, > anything else user can request. But that is not true. Based on the > config TDP level, this turbo (boost) start can be much below. For > example it can be 2300000 or any other value. > > This change adds an optional new attribute called "base_frequency", > which displays the max non-turbo frequency (base frequency). For example: > >cat base_frequency > 2200000 This is something very much acpi-cpufreq driver's specific and I don't really see other platform needing it. So, I would rather add this only for acpi-cpufreq driver, if at all it is required.
On 09/06/2015 11:06 PM, Viresh Kumar wrote: > On 04-09-15, 10:19, Srinivas Pandruvada wrote: >> Currently scaling_available_frequencies displays list of available >> frequencies which can be used to set max/min or current scaling >> frequency. But because of configurable thermal design power implementation >> in several Intel CPUs, this is not a guaranteed frequency or a P state, >> which user can request. After a limit all frequencies (P states) may be >> purely in opportunistic performance range. For example >> >>> cat scaling_available_frequencies >> 2301000 2300000 2200000 2000000 1900000 1800000 1700000 1500000 1400000 >> 1300000 1100000 1000000 900000 800000 600000 500000 >> >> Here traditionally it is assumed that only 2301000 is a turbo frequency, >> anything else user can request. But that is not true. Based on the >> config TDP level, this turbo (boost) start can be much below. For >> example it can be 2300000 or any other value. >> >> This change adds an optional new attribute called "base_frequency", >> which displays the max non-turbo frequency (base frequency). For example: >>> cat base_frequency >> 2200000 > This is something very much acpi-cpufreq driver's specific and I don't > really see other platform needing it. So, I would rather add this only > for acpi-cpufreq driver, if at all it is required. > I can only add to acpi cpufeq. Once configurable TDP becomes standard feature, I think others will follow. Thanks, Srinivas -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 07-09-15, 08:17, Srinivas pandruvada wrote: > I can only add to acpi cpufeq. Once configurable TDP becomes > standard feature, I think others will follow. We will move it to core then :)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 7a3c30c..f4ff667 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -812,6 +812,25 @@ static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); } +/* + * show_base_frequency - show the current cpufreq boost start freq + */ +static ssize_t show_base_frequency(struct cpufreq_policy *policy, char *buf) +{ + unsigned int freq; + int ret; + + if (cpufreq_driver->base_frequency) { + ret = cpufreq_driver->base_frequency(policy->cpu, &freq); + if (!ret) + return sprintf(buf, "%u\n", freq); + else + return ret; + } + + return -EIO; +} + cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); cpufreq_freq_attr_ro(cpuinfo_min_freq); cpufreq_freq_attr_ro(cpuinfo_max_freq); @@ -820,6 +839,7 @@ cpufreq_freq_attr_ro(scaling_available_governors); cpufreq_freq_attr_ro(scaling_driver); cpufreq_freq_attr_ro(scaling_cur_freq); cpufreq_freq_attr_ro(bios_limit); +cpufreq_freq_attr_ro(base_frequency); cpufreq_freq_attr_ro(related_cpus); cpufreq_freq_attr_ro(affected_cpus); cpufreq_freq_attr_rw(scaling_min_freq); @@ -1057,6 +1077,12 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy, return ret; } + if (cpufreq_driver->base_frequency) { + ret = sysfs_create_file(&policy->kobj, &base_frequency.attr); + if (ret) + return ret; + } + return cpufreq_add_dev_symlink(policy); } diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index bde1e56..f95a61e 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -267,6 +267,8 @@ struct cpufreq_driver { /* optional */ int (*bios_limit)(int cpu, unsigned int *limit); + /* optional base_frequency */ + int (*base_frequency)(int cpu, unsigned int *freq); int (*exit)(struct cpufreq_policy *policy); void (*stop_cpu)(struct cpufreq_policy *policy);