Re: [tip:tracing/ftrace] tracing, genirq: add irq enter and exittrace events

From: Masami Hiramatsu
Date: Thu Feb 26 2009 - 11:34:34 EST


Jason Baron wrote:
Author: Jason Baron <jbaron@xxxxxxxxxx>
AuthorDate: Thu, 26 Feb 2009 10:11:05 -0500
Commit: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Thu, 26 Feb 2009 16:36:42 +0100

tracing, genirq: add irq enter and exit trace events

Impact: add new tracepoints

Add them to the generic IRQ code, that way every architecture
gets these new tracepoints, not just x86.

Using Steve's new 'TRACE_FORMAT', I can get function graph
trace as follows using the original two IRQ tracepoints:

3) | handle_IRQ_event() {
3) | /* (irq_handler_entry) irq=28 handler=eth0 */
3) | e1000_intr_msi() {
3) 2.460 us | __napi_schedule();
3) 9.416 us | }
3) | /* (irq_handler_exit) irq=28 handler=eth0 return=handled */
3) + 22.935 us | }

Signed-off-by: Jason Baron <jbaron@xxxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Acked-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Mathieu Desnoyers <compudj@xxxxxxxxxxxxxxxxxx>
Cc: "Frank Ch. Eigler" <fche@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

Looks good for me,
Thank you!

Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>




---
include/trace/irq.h | 9 +++++++++
include/trace/irq_event_types.h | 17 +++++++++++++++++
kernel/irq/handle.c | 6 ++++++
kernel/trace/events.c | 2 ++
4 files changed, 34 insertions(+), 0 deletions(-)

diff --git a/include/trace/irq.h b/include/trace/irq.h
new file mode 100644
index 0000000..ff5d449
--- /dev/null
+++ b/include/trace/irq.h
@@ -0,0 +1,9 @@
+#ifndef _TRACE_IRQ_H
+#define _TRACE_IRQ_H
+
+#include <linux/interrupt.h>
+#include <linux/tracepoint.h>
+
+#include <trace/irq_event_types.h>
+
+#endif
diff --git a/include/trace/irq_event_types.h b/include/trace/irq_event_types.h
new file mode 100644
index 0000000..5d0919f
--- /dev/null
+++ b/include/trace/irq_event_types.h
@@ -0,0 +1,17 @@
+
+/* use <trace/irq.h> instead */
+#ifndef TRACE_FORMAT
+# error Do not include this file directly.
+# error Unless you know what you are doing.
+#endif
+
+TRACE_FORMAT(irq_handler_entry,
+ TPPROTO(int irq, struct irqaction *action),
+ TPARGS(irq, action),
+ TPFMT("irq=%d handler=%s", irq, action->name));
+
+TRACE_FORMAT(irq_handler_exit,
+ TPPROTO(int irq, struct irqaction *action, int ret),
+ TPARGS(irq, action, ret),
+ TPFMT("irq=%d handler=%s return=%s",
+ irq, action->name, ret ? "handled" : "unhandled"));
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 3aba8d1..4709a7c 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -17,6 +17,7 @@
#include <linux/kernel_stat.h>
#include <linux/rculist.h>
#include <linux/hash.h>
+#include <trace/irq.h>
#include "internals.h"
@@ -316,6 +317,9 @@ irqreturn_t no_action(int cpl, void *dev_id)
return IRQ_NONE;
}
+DEFINE_TRACE(irq_handler_entry);
+DEFINE_TRACE(irq_handler_exit);
+
/**
* handle_IRQ_event - irq action chain handler
* @irq: the interrupt number
@@ -332,7 +336,9 @@ irqreturn_t handle_IRQ_event(unsigned int irq, struct irqaction *action)
local_irq_enable_in_hardirq();
do {
+ trace_irq_handler_entry(irq, action);
ret = action->handler(irq, action->dev_id);
+ trace_irq_handler_exit(irq, action, ret);
if (ret == IRQ_HANDLED)
status |= action->flags;
retval |= ret;
diff --git a/kernel/trace/events.c b/kernel/trace/events.c
index 38c89ee..3c75623 100644
--- a/kernel/trace/events.c
+++ b/kernel/trace/events.c
@@ -6,8 +6,10 @@
/* trace/<type>.h here */
#include <trace/sched.h>
+#include <trace/irq.h>
#include "trace_events.h"
/* trace/<type>_event_types.h here */
#include <trace/sched_event_types.h>
+#include <trace/irq_event_types.h>

--
Masami Hiramatsu

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

e-mail: mhiramat@xxxxxxxxxx

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