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authorIngo Molnar <mingo@elte.hu>2009-02-26 20:47:11 +0300
committerIngo Molnar <mingo@elte.hu>2009-02-26 20:44:06 +0300
commit14131f2f98ac350ee9e73faed916d2238a8b6a0d (patch)
treebf490d104276142e914f1245bbc9f44cb0d2bc9b /include/linux/trace_clock.h
parent6409c4da289d6905f7ae2bd0630438368439bda2 (diff)
downloadlinux-14131f2f98ac350ee9e73faed916d2238a8b6a0d.tar.xz
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>
Diffstat (limited to 'include/linux/trace_clock.h')
-rw-r--r--include/linux/trace_clock.h19
1 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/trace_clock.h b/include/linux/trace_clock.h
new file mode 100644
index 000000000000..7a8130384087
--- /dev/null
+++ b/include/linux/trace_clock.h
@@ -0,0 +1,19 @@
+#ifndef _LINUX_TRACE_CLOCK_H
+#define _LINUX_TRACE_CLOCK_H
+
+/*
+ * 3 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
+ */
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+extern u64 notrace trace_clock_local(void);
+extern u64 notrace trace_clock(void);
+extern u64 notrace trace_clock_global(void);
+
+#endif /* _LINUX_TRACE_CLOCK_H */