From e8628dd06d66f2e3965ec9742029b401d63434f1 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 18 Apr 2008 13:31:12 -0700 Subject: [PATCH] [CPUFREQ] expose cpufreq coordination requirements regardless of coordination mechanism Currently, affected_cpus shows which CPUs need to have their frequency coordinated in software. When hardware coordination is in use, the contents of this file appear the same as when no coordination is required. This can lead to some confusion among user-space programs, for example, that do not know that extra coordination is required to force a CPU core to a particular speed to control power consumption. To fix this, create a "related_cpus" attribute that always displays the coordination map regardless of whatever coordination strategy the cpufreq driver uses (sw or hw). If the cpufreq driver does not provide a value, fall back to policy->cpus. Signed-off-by: Darrick J. Wong Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 1 + drivers/cpufreq/cpufreq.c | 29 ++++++++++++++++++---- include/linux/cpufreq.h | 3 ++- 3 files changed, 27 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 8db8f73503b..b0c8208df9f 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -601,6 +601,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy) policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) { policy->cpus = perf->shared_cpu_map; } + policy->related_cpus = perf->shared_cpu_map; #ifdef CONFIG_SMP dmi_check_system(sw_any_bug_dmi_table); diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index d3575f5ec6d..7fce038fa57 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -583,15 +583,13 @@ out: i += sprintf(&buf[i], "\n"); return i; } -/** - * show_affected_cpus - show the CPUs affected by each transition - */ -static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) + +static ssize_t show_cpus(cpumask_t mask, char *buf) { ssize_t i = 0; unsigned int cpu; - for_each_cpu_mask(cpu, policy->cpus) { + for_each_cpu_mask(cpu, mask) { if (i) i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); @@ -602,6 +600,25 @@ static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) return i; } +/** + * show_related_cpus - show the CPUs affected by each transition even if + * hw coordination is in use + */ +static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) +{ + if (cpus_empty(policy->related_cpus)) + return show_cpus(policy->cpus, buf); + return show_cpus(policy->related_cpus, buf); +} + +/** + * show_affected_cpus - show the CPUs affected by each transition + */ +static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) +{ + return show_cpus(policy->cpus, buf); +} + static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, const char *buf, size_t count) { @@ -646,6 +663,7 @@ define_one_ro(cpuinfo_max_freq); define_one_ro(scaling_available_governors); define_one_ro(scaling_driver); define_one_ro(scaling_cur_freq); +define_one_ro(related_cpus); define_one_ro(affected_cpus); define_one_rw(scaling_min_freq); define_one_rw(scaling_max_freq); @@ -658,6 +676,7 @@ static struct attribute *default_attrs[] = { &scaling_min_freq.attr, &scaling_max_freq.attr, &affected_cpus.attr, + &related_cpus.attr, &scaling_governor.attr, &scaling_driver.attr, &scaling_available_governors.attr, diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index ddd8652fc3f..a881fd62c44 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -83,7 +83,8 @@ struct cpufreq_real_policy { }; struct cpufreq_policy { - cpumask_t cpus; /* affected CPUs */ + cpumask_t cpus; /* CPUs requiring sw coordination */ + cpumask_t related_cpus; /* CPUs with any coordination */ unsigned int shared_type; /* ANY or ALL affected CPUs should set cpufreq */ unsigned int cpu; /* cpu nr of registered CPU */ -- 2.41.0