Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756034AbYCUAoQ (ORCPT ); Thu, 20 Mar 2008 20:44:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752046AbYCUAn7 (ORCPT ); Thu, 20 Mar 2008 20:43:59 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:40686 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751596AbYCUAn6 (ORCPT ); Thu, 20 Mar 2008 20:43:58 -0400 Date: Thu, 20 Mar 2008 17:43:54 -0700 From: "Darrick J. Wong" To: cpufreq@lists.linux.org.uk Cc: linux-kernel , "Pallipadi, Venkatesh" Subject: [PATCH] cpufreq: Expose cpufreq coordination requirements regardless of coordination mechanism Message-ID: <20080321004354.GQ5529@tree.beaverton.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4229 Lines: 116 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 --- 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 a962dcb..2e21d35 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -591,6 +591,7 @@ 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 35a26a3..38bf03f 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -582,15 +582,13 @@ 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); @@ -601,6 +599,25 @@ 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) { @@ -645,6 +662,7 @@ 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); @@ -657,6 +675,7 @@ 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 ddd8652..a881fd6 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 */ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/