acpi-cpufreq: Add new sysfs attribute freqdomain_cpus
Commits fcf8058 (cpufreq: Simplify cpufreq_add_dev()) and aa77a52
(cpufreq: acpi-cpufreq: Don't set policy->related_cpus from .init())
changed the contents of the "related_cpus" sysfs attribute on systems
where acpi-cpufreq is used and user space can't get the list of CPUs
which are in the same hardware coordination CPU domain (provided by
the ACPI AML method _PSD) via "related_cpus" any more.
To make up for that loss add a new sysfs attribute "freqdomian_cpus"
for the acpi-cpufreq driver which exposes the list of CPUs in the
same domain regardless of whether it is coordinated by hardware or
software.
[rjw: Changelog, documentation]
References: https://bugzilla.kernel.org/show_bug.cgi?id=58761
Reported-by: Jean-Philippe Halimi <jean-philippe.halimi@exascale-computing.eu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 2447698..468e4d4 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -144,6 +144,21 @@
to learn how to control the knobs.
+What: /sys/devices/system/cpu/cpu#/cpufreq/freqdomain_cpus
+Date: June 2013
+Contact: cpufreq@vger.kernel.org
+Description: Discover CPUs in the same CPU frequency coordination domain
+
+ freqdomain_cpus is the list of CPUs (online+offline) that share
+ the same clock/freq domain (possibly at the hardware level).
+ That information may be hidden from the cpufreq core and the
+ value of related_cpus may be different from freqdomain_cpus. This
+ attribute is useful for user space DVFS controllers to get better
+ power/performance results for platforms using acpi-cpufreq.
+
+ This file is only present if the acpi-cpufreq driver is in use.
+
+
What: /sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1}
Date: August 2008
KernelVersion: 2.6.27