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authorMike Chan <mike@android.com>2010-05-10 17:54:48 -0700
committerColin Cross <ccross@android.com>2010-09-29 17:49:41 -0700
commit8d8e56b794316003db0e9736f95ad7196fc81c68 (patch)
treeb957da9b6920f7cb54dc32a9cc44ae0487f4664f /kernel
parent73b1c8a4ea3b04e306e31f297d3e39728bc854c2 (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 'kernel')
-rw-r--r--kernel/sched.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 39e1666fb72d..c9761c1ec4a4 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -72,6 +72,7 @@
#include <linux/ctype.h>
#include <linux/ftrace.h>
#include <linux/slab.h>
+#include <linux/cpuacct.h>
#include <asm/tlb.h>
#include <asm/irq_regs.h>
@@ -8878,8 +8879,30 @@ struct cpuacct {
u64 __percpu *cpuusage;
struct percpu_counter cpustat[CPUACCT_STAT_NSTATS];
struct cpuacct *parent;
+ struct cpuacct_charge_calls *cpufreq_fn;
+ void *cpuacct_data;
};
+static struct cpuacct *cpuacct_root;
+
+/* Default calls for cpufreq accounting */
+static struct cpuacct_charge_calls *cpuacct_cpufreq;
+int cpuacct_register_cpufreq(struct cpuacct_charge_calls *fn)
+{
+ cpuacct_cpufreq = fn;
+
+ /*
+ * Root node is created before platform can register callbacks,
+ * initalize here.
+ */
+ if (cpuacct_root && fn) {
+ cpuacct_root->cpufreq_fn = fn;
+ if (fn->init)
+ fn->init(&cpuacct_root->cpuacct_data);
+ }
+ return 0;
+}
+
struct cgroup_subsys cpuacct_subsys;
/* return cpu accounting group corresponding to this container */
@@ -8914,8 +8937,16 @@ static struct cgroup_subsys_state *cpuacct_create(
if (percpu_counter_init(&ca->cpustat[i], 0))
goto out_free_counters;
+ ca->cpufreq_fn = cpuacct_cpufreq;
+
+ /* If available, have platform code initalize cpu frequency table */
+ if (ca->cpufreq_fn && ca->cpufreq_fn->init)
+ ca->cpufreq_fn->init(&ca->cpuacct_data);
+
if (cgrp->parent)
ca->parent = cgroup_ca(cgrp->parent);
+ else
+ cpuacct_root = ca;
return &ca->css;
@@ -9043,6 +9074,16 @@ static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft,
return 0;
}
+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);
+
+ return 0;
+}
+
static struct cftype files[] = {
{
.name = "usage",
@@ -9057,6 +9098,10 @@ static struct cftype files[] = {
.name = "stat",
.read_map = cpuacct_stats_show,
},
+ {
+ .name = "cpufreq",
+ .read_map = cpuacct_cpufreq_show,
+ },
};
static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
@@ -9086,6 +9131,10 @@ static void cpuacct_charge(struct task_struct *tsk, u64 cputime)
for (; ca; ca = ca->parent) {
u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu);
*cpuusage += cputime;
+
+ /* Call back into platform code to account for CPU speeds */
+ if (ca->cpufreq_fn && ca->cpufreq_fn->charge)
+ ca->cpufreq_fn->charge(ca->cpuacct_data, cputime, cpu);
}
rcu_read_unlock();