[RFC][Patch 2/2] markers: example of irq regular kernel markers

[Masami Hiramatsu <mhiramat@redhat.com>]

Add trace points of irq handle events ported from LTTng's markers.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
---
I just rewrote LTTng's irq event by using DEFINE_TRACE for example.

 include/linux/irq_trace.h |    6 ++++++
 kernel/irq/handle.c       |    6 ++++++
 2 files changed, 12 insertions(+)

Index: 2.6.26-rc5-mm3/include/linux/irq_trace.h
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ 2.6.26-rc5-mm3/include/linux/irq_trace.h	2008-06-16 12:27:51.000000000 -0400
@@ -0,0 +1,6 @@
+#include <linux/marker.h>
+
+DEFINE_TRACE(irq_entry, (int irq_id, int kernel_mode), irq_id, kernel_mode);
+
+DEFINE_TRACE(irq_exit, (void));
+
Index: 2.6.26-rc5-mm3/kernel/irq/handle.c
===================================================================
--- 2.6.26-rc5-mm3.orig/kernel/irq/handle.c	2008-06-16 12:27:50.000000000 -0400
+++ 2.6.26-rc5-mm3/kernel/irq/handle.c	2008-06-16 12:27:51.000000000 -0400
@@ -15,6 +15,7 @@
 #include <linux/random.h>
 #include <linux/interrupt.h>
 #include <linux/kernel_stat.h>
+#include <linux/irq_trace.h>

 #include "internals.h"

@@ -130,6 +131,9 @@ irqreturn_t handle_IRQ_event(unsigned in
 {
 	irqreturn_t ret, retval = IRQ_NONE;
 	unsigned int status = 0;
+	struct pt_regs *regs = get_irq_regs();
+
+	trace_irq_entry(irq, (regs)?(!user_mode(regs)):(1));

 	handle_dynamic_tick(action);

@@ -148,6 +152,8 @@ irqreturn_t handle_IRQ_event(unsigned in
 		add_interrupt_randomness(irq);
 	local_irq_disable();

+	trace_irq_exit();
+
 	return retval;
 }

-- 
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division

e-mail: mhiramat@redhat.com