tracing/sched: Add trace events to track cpu hotplug.
Add ftrace event trace_sched_cpu_hotplug to track cpu
hot-add and hot-remove events.
This is useful in a variety of power, performance and
debug analysis scenarios.
Change-Id: I5d202c7a229ffacc3aafb7cf9afee0b0ee7b0931
Signed-off-by: Arun Bharadwaj <abharadw@codeaurora.org>
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 975b1a5..2912551 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -17,6 +17,8 @@
#include <linux/gfp.h>
#include <linux/suspend.h>
+#include <trace/events/sched.h>
+
#ifdef CONFIG_SMP
/* Serializes the updates to cpu_online_mask, cpu_present_mask */
static DEFINE_MUTEX(cpu_add_remove_lock);
@@ -290,6 +292,7 @@
out_release:
cpu_hotplug_done();
+ trace_sched_cpu_hotplug(cpu, err, 0);
if (!err)
cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
return err;
@@ -347,6 +350,7 @@
if (ret != 0)
__cpu_notify(CPU_UP_CANCELED | mod, hcpu, nr_calls, NULL);
cpu_hotplug_done();
+ trace_sched_cpu_hotplug(cpu, ret, 1);
return ret;
}