tracing: Add tracepoints for hotplug
Andy Park [Tue, 1 May 2012 15:53:26 +0000 (08:53 -0700)]
Simple trace points for measuring hotplug up/down times.

Bug 960310

Change-Id: I74dd3c5cddcc1ded02ad08a7ce38bacf3147ee3e
Reviewed-on: http://git-master/r/99806
Reviewed-by: Andy Park <andyp@nvidia.com>
Tested-by: Andy Park <andyp@nvidia.com>
Reviewed-by: Prajakta Gudadhe <pgudadhe@nvidia.com>

include/trace/events/power.h
kernel/cpu.c

index 1bcc2a8..be23253 100644 (file)
@@ -39,8 +39,37 @@ DEFINE_EVENT(cpu, cpu_idle,
 #define _PWR_EVENT_AVOID_DOUBLE_DEFINING
 
 #define PWR_EVENT_EXIT -1
+
+enum {
+       POWER_CPU_UP_START,
+       POWER_CPU_UP_DONE,
+       POWER_CPU_DOWN_START,
+       POWER_CPU_DOWN_DONE,
+};
+
 #endif
 
+TRACE_EVENT(cpu_hotplug,
+
+       TP_PROTO(unsigned int cpu_id, int state),
+
+       TP_ARGS(cpu_id, state),
+
+       TP_STRUCT__entry(
+               __field(u32, cpu_id)
+               __field(u32, state)
+       ),
+
+       TP_fast_assign(
+               __entry->cpu_id = cpu_id;
+               __entry->state = state;
+       ),
+
+       TP_printk("cpu_id=%lu, state=%lu",
+                 (unsigned long)__entry->cpu_id,
+                 (unsigned long)__entry->state)
+);
+
 DEFINE_EVENT(cpu, cpu_frequency,
 
        TP_PROTO(unsigned int frequency, unsigned int cpu_id),
index eae3d9b..f9bb3d4 100644 (file)
@@ -16,6 +16,7 @@
 #include <linux/mutex.h>
 #include <linux/gfp.h>
 #include <linux/suspend.h>
+#include <trace/events/power.h>
 
 #ifdef CONFIG_SMP
 /* Serializes the updates to cpu_online_mask, cpu_present_mask */
@@ -274,6 +275,8 @@ int __ref cpu_down(unsigned int cpu)
 {
        int err;
 
+       trace_cpu_hotplug(cpu, POWER_CPU_DOWN_START);
+
        cpu_maps_update_begin();
 
        if (cpu_hotplug_disabled) {
@@ -285,6 +288,7 @@ int __ref cpu_down(unsigned int cpu)
 
 out:
        cpu_maps_update_done();
+       trace_cpu_hotplug(cpu, POWER_CPU_DOWN_DONE);
        return err;
 }
 EXPORT_SYMBOL(cpu_down);
@@ -335,6 +339,8 @@ int __cpuinit cpu_up(unsigned int cpu)
        pg_data_t       *pgdat;
 #endif
 
+       trace_cpu_hotplug(cpu, POWER_CPU_UP_START);
+
        if (!cpu_possible(cpu)) {
                printk(KERN_ERR "can't online cpu %d because it is not "
                        "configured as may-hotadd at boot time\n", cpu);
@@ -378,6 +384,7 @@ int __cpuinit cpu_up(unsigned int cpu)
 
 out:
        cpu_maps_update_done();
+       trace_cpu_hotplug(cpu, POWER_CPU_UP_DONE);
        return err;
 }