tracing: implement trace_clock_*() APIs
Impact: implement new tracing timestamp APIs
Add three trace clock variants, with differing scalability/precision
tradeoffs:
- local: CPU-local trace clock
- medium: scalable global clock with some jitter
- global: globally monotonic, serialized clock
Make the ring-buffer use the local trace clock internally.
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 8f19f1a..a8c275c 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -4,6 +4,7 @@
* Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
*/
#include <linux/ring_buffer.h>
+#include <linux/trace_clock.h>
#include <linux/ftrace_irq.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>
@@ -12,7 +13,6 @@
#include <linux/module.h>
#include <linux/percpu.h>
#include <linux/mutex.h>
-#include <linux/sched.h> /* used for sched_clock() (for now) */
#include <linux/init.h>
#include <linux/hash.h>
#include <linux/list.h>
@@ -112,14 +112,13 @@
/* Up this if you want to test the TIME_EXTENTS and normalization */
#define DEBUG_SHIFT 0
-/* FIXME!!! */
u64 ring_buffer_time_stamp(int cpu)
{
u64 time;
preempt_disable_notrace();
/* shift to debug/test normalization and TIME_EXTENTS */
- time = sched_clock() << DEBUG_SHIFT;
+ time = trace_clock_local() << DEBUG_SHIFT;
preempt_enable_no_resched_notrace();
return time;