linux-kernel - [for-next][PATCH 03/20] ftrace: Separate unlimited probes from count limited probes

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Date:	Fri, 15 Mar 2013 15:39:38 -0400
From:	Steven Rostedt <rostedt@...dmis.org>
To:	linux-kernel@...r.kernel.org
Cc:	Ingo Molnar <mingo@...nel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Frederic Weisbecker <fweisbec@...il.com>
Subject: [for-next][PATCH 03/20] ftrace: Separate unlimited probes from count limited probes

From: "Steven Rostedt (Red Hat)" <rostedt@...dmis.org>

The function tracing probes that trigger traceon or traceoff can be
set to unlimited, or given a count of # of times to execute.

By separating these two types of probes, we can then use the dynamic
ftrace function filtering directly, and remove the brute force
"check if this function called is my probe" routines in ftrace.

Signed-off-by: Steven Rostedt <rostedt@...dmis.org>
---
 kernel/trace/trace_functions.c |   38 +++++++++++++++++++++++++++++++++-----
 1 file changed, 33 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index a88a3e0..043b242 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -228,7 +228,7 @@ static int update_count(void **data)
 }
 
 static void
-ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_traceon_count(unsigned long ip, unsigned long parent_ip, void **data)
 {
 	if (tracing_is_on())
 		return;
@@ -238,7 +238,7 @@ ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
 }
 
 static void
-ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
+ftrace_traceoff_count(unsigned long ip, unsigned long parent_ip, void **data)
 {
 	if (!tracing_is_on())
 		return;
@@ -247,10 +247,38 @@ ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
 		tracing_off();
 }
 
+static void
+ftrace_traceon(unsigned long ip, unsigned long parent_ip, void **data)
+{
+	if (tracing_is_on())
+		return;
+
+	tracing_on();
+}
+
+static void
+ftrace_traceoff(unsigned long ip, unsigned long parent_ip, void **data)
+{
+	if (!tracing_is_on())
+		return;
+
+	tracing_off();
+}
+
 static int
 ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
 			 struct ftrace_probe_ops *ops, void *data);
 
+static struct ftrace_probe_ops traceon_count_probe_ops = {
+	.func			= ftrace_traceon_count,
+	.print			= ftrace_trace_onoff_print,
+};
+
+static struct ftrace_probe_ops traceoff_count_probe_ops = {
+	.func			= ftrace_traceoff_count,
+	.print			= ftrace_trace_onoff_print,
+};
+
 static struct ftrace_probe_ops traceon_probe_ops = {
 	.func			= ftrace_traceon,
 	.print			= ftrace_trace_onoff_print,
@@ -269,7 +297,7 @@ ftrace_trace_onoff_print(struct seq_file *m, unsigned long ip,
 
 	seq_printf(m, "%ps:", (void *)ip);
 
-	if (ops == &traceon_probe_ops)
+	if (ops == &traceon_probe_ops || ops == &traceon_count_probe_ops)
 		seq_printf(m, "traceon");
 	else
 		seq_printf(m, "traceoff");
@@ -297,9 +325,9 @@ ftrace_trace_onoff_callback(struct ftrace_hash *hash,
 
 	/* we register both traceon and traceoff to this callback */
 	if (strcmp(cmd, "traceon") == 0)
-		ops = &traceon_probe_ops;
+		ops = param ? &traceon_count_probe_ops : &traceon_probe_ops;
 	else
-		ops = &traceoff_probe_ops;
+		ops = param ? &traceoff_count_probe_ops : &traceoff_probe_ops;
 
 	if (glob[0] == '!') {
 		unregister_ftrace_function_probe_func(glob+1, ops);
-- 
1.7.10.4



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