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authorDavid Sharp <dhsharp@google.com>2012-11-13 12:18:21 -0800
committerSteven Rostedt <rostedt@goodmis.org>2012-11-13 15:48:27 -0500
commit8cbd9cc6254065c97c4bac42daa55ba1abe73a8e (patch)
treebb52f23f66fc6288e7efbce76ee389af0b52cc85 /include/asm-generic
parent7bcfaf54f591a0775254c4ea679faf615152ee3a (diff)
downloadlinux-8cbd9cc6254065c97c4bac42daa55ba1abe73a8e.tar.bz2
tracing,x86: Add a TSC trace_clock
In order to promote interoperability between userspace tracers and ftrace, add a trace_clock that reports raw TSC values which will then be recorded in the ring buffer. Userspace tracers that also record TSCs are then on exactly the same time base as the kernel and events can be unambiguously interlaced. Tested: Enabled a tracepoint and the "tsc" trace_clock and saw very large timestamp values. v2: Move arch-specific bits out of generic code. v3: Rename "x86-tsc", cleanups v7: Generic arch bits in Kbuild. Google-Bug-Id: 6980623 Link: http://lkml.kernel.org/r/1352837903-32191-1-git-send-email-dhsharp@google.com Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@linux.intel.com> Signed-off-by: David Sharp <dhsharp@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/trace_clock.h16
1 files changed, 16 insertions, 0 deletions
diff --git a/include/asm-generic/trace_clock.h b/include/asm-generic/trace_clock.h
new file mode 100644
index 000000000000..6726f1bafb5e
--- /dev/null
+++ b/include/asm-generic/trace_clock.h
@@ -0,0 +1,16 @@
+#ifndef _ASM_GENERIC_TRACE_CLOCK_H
+#define _ASM_GENERIC_TRACE_CLOCK_H
+/*
+ * Arch-specific trace clocks.
+ */
+
+/*
+ * Additional trace clocks added to the trace_clocks
+ * array in kernel/trace/trace.c
+ * None if the architecture has not defined it.
+ */
+#ifndef ARCH_TRACE_CLOCKS
+# define ARCH_TRACE_CLOCKS
+#endif
+
+#endif /* _ASM_GENERIC_TRACE_CLOCK_H */