scheduler: cpuacct: Enable platform callbacks for cpuacct power tracking
Mike Chan [Wed, 12 May 2010 22:52:14 +0000 (15:52 -0700)]
Platform must register cpu power function that return power in
milliWatt seconds.

Change-Id: I1caa0335e316c352eee3b1ddf326fcd4942bcbe8
Signed-off-by: Mike Chan <mike@android.com>

Documentation/cgroups/cpuacct.txt
include/linux/cpuacct.h
kernel/sched.c

index ac8c648..e21a932 100644 (file)
@@ -43,6 +43,9 @@ 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.power file gives CPU power consumed (in milliWatt seconds). Platform
+must provide and implement power callback functions.
+
 cpuacct controller uses percpu_counter interface to collect user and
 system times. This has two side effects:
 
index 560df02..8f68e73 100644 (file)
@@ -31,7 +31,9 @@ struct cpuacct_charge_calls {
         */
        void (*init) (void **cpuacct_data);
        void (*charge) (void *cpuacct_data,  u64 cputime, unsigned int cpu);
-       void (*show) (void *cpuacct_data, struct cgroup_map_cb *cb);
+       void (*cpufreq_show) (void *cpuacct_data, struct cgroup_map_cb *cb);
+       /* Returns power consumed in milliWatt seconds */
+       u64 (*power_usage) (void *cpuacct_data);
 };
 
 int cpuacct_charge_register(struct cpuacct_charge_calls *fn);
index a011859..27ee31e 100644 (file)
@@ -9304,12 +9304,28 @@ static int cpuacct_cpufreq_show(struct cgroup *cgrp, struct cftype *cft,
                struct cgroup_map_cb *cb)
 {
        struct cpuacct *ca = cgroup_ca(cgrp);
-       if (ca->cpufreq_fn && ca->cpufreq_fn->show)
-               ca->cpufreq_fn->show(ca->cpuacct_data, cb);
+       if (ca->cpufreq_fn && ca->cpufreq_fn->cpufreq_show)
+               ca->cpufreq_fn->cpufreq_show(ca->cpuacct_data, cb);
 
        return 0;
 }
 
+/* return total cpu power usage (milliWatt second) of a group */
+static u64 cpuacct_powerusage_read(struct cgroup *cgrp, struct cftype *cft)
+{
+       int i;
+       struct cpuacct *ca = cgroup_ca(cgrp);
+       u64 totalpower = 0;
+
+       if (ca->cpufreq_fn && ca->cpufreq_fn->power_usage)
+               for_each_present_cpu(i) {
+                       totalpower += ca->cpufreq_fn->power_usage(
+                                       ca->cpuacct_data);
+               }
+
+       return totalpower;
+}
+
 static struct cftype files[] = {
        {
                .name = "usage",
@@ -9328,6 +9344,10 @@ static struct cftype files[] = {
                .name =  "cpufreq",
                .read_map = cpuacct_cpufreq_show,
        },
+       {
+               .name = "power",
+               .read_u64 = cpuacct_powerusage_read
+       },
 };
 
 static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)