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authorMike Chan <mike@android.com>2010-05-10 17:54:48 -0700
committerBrian Swetland <swetland@google.com>2011-03-29 13:57:56 -0700
commit8b995e8bb336cf0fc35391abbc2f89c8b6779483 (patch)
tree51da67266db4e7fb6ca31dc482a4f259d34dab67 /Documentation
parentef5cdec6ecced9ea2e58d33ea8ee7a53d927f2cb (diff)
scheduler: cpuacct: Enable platform hooks to track cpuusage for CPU frequencies
Introduce new platform callback hooks for cpuacct for tracking CPU frequencies Not all platforms / architectures have a set CPU_FREQ_TABLE defined for CPU transition speeds. In order to track time spent in at various CPU frequencies, we enable platform callbacks from cpuacct for this accounting. Architectures that support overclock boosting, or don't have pre-defined frequency tables can implement their own bucketing system that makes sense given their cpufreq scaling abilities. New file: cpuacct.cpufreq reports the CPU time (in nanoseconds) spent at each CPU frequency. Change-Id: I10a80b3162e6fff3a8a2f74dd6bb37e88b12ba96 Signed-off-by: Mike Chan <mike@android.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/cgroups/cpuacct.txt4
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/cgroups/cpuacct.txt b/Documentation/cgroups/cpuacct.txt
index 8b930946c52a..600d2d0b85f0 100644
--- a/Documentation/cgroups/cpuacct.txt
+++ b/Documentation/cgroups/cpuacct.txt
@@ -40,6 +40,10 @@ system: Time spent by tasks of the cgroup in kernel mode.
user and system are in USER_HZ unit.
+cpuacct.cpufreq file gives CPU time (in nanoseconds) spent at each CPU
+frequency. Platform hooks must be implemented inorder to properly track
+time at each CPU frequency.
+
cpuacct controller uses percpu_counter interface to collect user and
system times. This has two side effects: