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>

1 files changed, 41 insertions, 0 deletions

diff --git a/include/linux/cpuacct.h b/include/linux/cpuacct.h
new file mode 100644
index 00000000000..560df02f098
--- /dev/null
+++ b/include/linux/cpuacct.h
@@ -0,0 +1,41 @@
+/* include/linux/cpuacct.h
+ *
+ * Copyright (C) 2010 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _CPUACCT_H_
+#define _CPUACCT_H_
+
+#include <linux/cgroup.h>
+
+#ifdef CONFIG_CGROUP_CPUACCT
+
+/*
+ * Platform specific CPU frequency hooks for cpuacct. These functions are
+ * called from the scheduler.
+ */
+struct cpuacct_charge_calls {
+	/*
+	 * Platforms can take advantage of this data and use
+	 * per-cpu allocations if necessary.
+	 */
+	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);
+};
+
+int cpuacct_charge_register(struct cpuacct_charge_calls *fn);
+
+#endif /* CONFIG_CGROUP_CPUACCT */
+
+#endif // _CPUACCT_H_