From 07695fa04e8a3384b0c855398ce1f7885bd7dc3b Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Fri, 31 Oct 2008 13:08:28 +0100
Subject: tracing/ftrace: fix a race condition in sched_switch tracer

Impact: fix race condition in sched_switch tracer

This patch fixes a race condition in the sched_switch tracer. If
several tasks (IE: concurrent initcalls) are playing with
tracing_start_cmdline_record() and tracing_stop_cmdline_record(), the
following situation could happen:

_ Task A and B are using the same tracepoint probe. Task A holds it.
  Task B is sleeping and doesn't hold it.

_ Task A frees the sched tracer, then sched_ref is decremented to 0.

_ Task A is preempted and hadn't yet unregistered its tracepoint
  probe, then B runs.

_ B increments sched_ref, sees it's 1 and then guess it has to
  register its probe. But it has not been freed by task A.

_ A lot of bad things can happen after that...

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace_sched_switch.c | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index b8f56beb1a62..59de5141207c 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -17,6 +17,7 @@
 static struct trace_array	*ctx_trace;
 static int __read_mostly	tracer_enabled;
 static atomic_t			sched_ref;
+static DEFINE_MUTEX(tracepoint_mutex);
 
 static void
 probe_sched_switch(struct rq *__rq, struct task_struct *prev,
@@ -125,18 +126,22 @@ static void tracing_start_sched_switch(void)
 {
 	long ref;
 
+	mutex_lock(&tracepoint_mutex);
 	ref = atomic_inc_return(&sched_ref);
 	if (ref == 1)
 		tracing_sched_register();
+	mutex_unlock(&tracepoint_mutex);
 }
 
 static void tracing_stop_sched_switch(void)
 {
 	long ref;
 
+	mutex_lock(&tracepoint_mutex);
 	ref = atomic_dec_and_test(&sched_ref);
 	if (ref)
 		tracing_sched_unregister();
+	mutex_unlock(&tracepoint_mutex);
 }
 
 void tracing_start_cmdline_record(void)
-- 
cgit v1.2.3-59-g8ed1b


From e55f605c14679c30be41473e60b7ad26524cdc35 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Fri, 31 Oct 2008 13:14:28 +0100
Subject: tracing/ftrace: remove unused code in sched_switch tracer

Impact: cleanup

When init_sched_switch_trace() is called, it has no reason to start
the sched tracer if the sched_ref is not zero.

_ If this is non-zero, the tracer is already used, but we can register it
to the tracing engine. There is already a security which avoid the tracer
probes not to be resgistered twice.

_ If this is zero, this block will not be used.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace_sched_switch.c | 8 --------
 1 file changed, 8 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 59de5141207c..96620c714300 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -203,14 +203,6 @@ static struct tracer sched_switch_trace __read_mostly =
 
 __init static int init_sched_switch_trace(void)
 {
-	int ret = 0;
-
-	if (atomic_read(&sched_ref))
-		ret = tracing_sched_register();
-	if (ret) {
-		pr_info("error registering scheduler trace\n");
-		return ret;
-	}
 	return register_tracer(&sched_switch_trace);
 }
 device_initcall(init_sched_switch_trace);
-- 
cgit v1.2.3-59-g8ed1b


From d7ad44b697c9d13e445ddc7d16f736fbac333249 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Fri, 31 Oct 2008 13:20:08 +0100
Subject: tracing/fastboot: use sched switch tracer from boot tracer

Impact: enhance boot trace output with scheduling events

Use the sched_switch tracer from the boot tracer.

We also can trace schedule events inside the initcalls.
Sched tracing is disabled after the initcall has finished and
then reenabled before the next one is started.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace.c              | 2 ++
 kernel/trace/trace.h              | 1 +
 kernel/trace/trace_boot.c         | 6 ++++++
 kernel/trace/trace_sched_switch.c | 6 +++---
 4 files changed, 12 insertions(+), 3 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index e4c40c868d67..50d7018163f6 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3251,6 +3251,8 @@ __init static int tracer_alloc_buffers(void)
 
 	register_tracer(&nop_trace);
 #ifdef CONFIG_BOOT_TRACER
+	/* We don't want to launch sched_switch tracer yet */
+	global_trace.ctrl = 0;
 	register_tracer(&boot_tracer);
 	current_trace = &boot_tracer;
 	current_trace->init(&global_trace);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 8465ad052707..9911277b268b 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -49,6 +49,7 @@ struct ftrace_entry {
 	unsigned long		parent_ip;
 };
 extern struct tracer boot_tracer;
+extern struct tracer sched_switch_trace; /* Used by the boot tracer */
 
 /*
  * Context switch trace entry - which task (and prio) we switched from/to:
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index d104d5b46413..6bbc8794a6df 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -27,10 +27,14 @@ void start_boot_trace(void)
 
 void enable_boot_trace(void)
 {
+	if (pre_initcalls_finished)
+		tracing_start_cmdline_record();
 }
 
 void disable_boot_trace(void)
 {
+	if (pre_initcalls_finished)
+		tracing_stop_cmdline_record();
 }
 
 void reset_boot_trace(struct trace_array *tr)
@@ -45,6 +49,8 @@ static void boot_trace_init(struct trace_array *tr)
 
 	for_each_cpu_mask(cpu, cpu_possible_map)
 		tracing_reset(tr, cpu);
+
+	sched_switch_trace.init(tr);
 }
 
 static void boot_trace_ctrl_update(struct trace_array *tr)
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 96620c714300..9d7bdac331dd 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -127,6 +127,7 @@ static void tracing_start_sched_switch(void)
 	long ref;
 
 	mutex_lock(&tracepoint_mutex);
+	tracer_enabled = 1;
 	ref = atomic_inc_return(&sched_ref);
 	if (ref == 1)
 		tracing_sched_register();
@@ -138,6 +139,7 @@ static void tracing_stop_sched_switch(void)
 	long ref;
 
 	mutex_lock(&tracepoint_mutex);
+	tracer_enabled = 0;
 	ref = atomic_dec_and_test(&sched_ref);
 	if (ref)
 		tracing_sched_unregister();
@@ -158,12 +160,10 @@ static void start_sched_trace(struct trace_array *tr)
 {
 	sched_switch_reset(tr);
 	tracing_start_cmdline_record();
-	tracer_enabled = 1;
 }
 
 static void stop_sched_trace(struct trace_array *tr)
 {
-	tracer_enabled = 0;
 	tracing_stop_cmdline_record();
 }
 
@@ -190,7 +190,7 @@ static void sched_switch_trace_ctrl_update(struct trace_array *tr)
 		stop_sched_trace(tr);
 }
 
-static struct tracer sched_switch_trace __read_mostly =
+struct tracer sched_switch_trace __read_mostly =
 {
 	.name		= "sched_switch",
 	.init		= sched_switch_trace_init,
-- 
cgit v1.2.3-59-g8ed1b


From efade6e7821c4219818e9da08f9315dfa617048b Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Fri, 31 Oct 2008 13:28:58 +0100
Subject: tracing/ftrace: types and naming corrections for sched tracer

Impact: cleanup

This patch applies some corrections suggested by Steven Rostedt.

Change the type of shed_ref into int since it is used
into a Mutex, we don't need it anymore as an atomic
variable in the sched_switch tracer.
Also change the name of the register mutex.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace_sched_switch.c | 30 +++++++++++++-----------------
 1 file changed, 13 insertions(+), 17 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 9d7bdac331dd..969953bf678f 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -16,8 +16,8 @@
 
 static struct trace_array	*ctx_trace;
 static int __read_mostly	tracer_enabled;
-static atomic_t			sched_ref;
-static DEFINE_MUTEX(tracepoint_mutex);
+static int			sched_ref;
+static DEFINE_MUTEX(sched_register_mutex);
 
 static void
 probe_sched_switch(struct rq *__rq, struct task_struct *prev,
@@ -28,7 +28,7 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev,
 	int cpu;
 	int pc;
 
-	if (!atomic_read(&sched_ref))
+	if (!sched_ref)
 		return;
 
 	tracing_record_cmdline(prev);
@@ -124,26 +124,22 @@ static void tracing_sched_unregister(void)
 
 static void tracing_start_sched_switch(void)
 {
-	long ref;
-
-	mutex_lock(&tracepoint_mutex);
-	tracer_enabled = 1;
-	ref = atomic_inc_return(&sched_ref);
-	if (ref == 1)
+	mutex_lock(&sched_register_mutex);
+	if (!(sched_ref++)) {
+		tracer_enabled = 1;
 		tracing_sched_register();
-	mutex_unlock(&tracepoint_mutex);
+	}
+	mutex_unlock(&sched_register_mutex);
 }
 
 static void tracing_stop_sched_switch(void)
 {
-	long ref;
-
-	mutex_lock(&tracepoint_mutex);
-	tracer_enabled = 0;
-	ref = atomic_dec_and_test(&sched_ref);
-	if (ref)
+	mutex_lock(&sched_register_mutex);
+	if (!(--sched_ref)) {
 		tracing_sched_unregister();
-	mutex_unlock(&tracepoint_mutex);
+		tracer_enabled = 0;
+	}
+	mutex_unlock(&sched_register_mutex);
 }
 
 void tracing_start_cmdline_record(void)
-- 
cgit v1.2.3-59-g8ed1b


From 79a9d461fd521f133f0e66485aa9ed09c21f5191 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Fri, 31 Oct 2008 13:34:45 +0100
Subject: tracing/ftrace: fix a bug when switch current tracer to sched tracer

Impact: fix boot tracer + sched tracer coupling bug

Fix a bug that made the sched_switch tracer unable to run
if set as the current_tracer after the boot tracer.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace_boot.c         | 4 ++--
 kernel/trace/trace_sched_switch.c | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 6bbc8794a6df..bd5046c9deb7 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -37,9 +37,9 @@ void disable_boot_trace(void)
 		tracing_stop_cmdline_record();
 }
 
-void reset_boot_trace(struct trace_array *tr)
+static void reset_boot_trace(struct trace_array *tr)
 {
-	disable_boot_trace();
+	sched_switch_trace.reset(tr);
 }
 
 static void boot_trace_init(struct trace_array *tr)
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 969953bf678f..888944d3409d 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -173,7 +173,7 @@ static void sched_switch_trace_init(struct trace_array *tr)
 
 static void sched_switch_trace_reset(struct trace_array *tr)
 {
-	if (tr->ctrl)
+	if (tr->ctrl && sched_ref)
 		stop_sched_trace(tr);
 }
 
-- 
cgit v1.2.3-59-g8ed1b


From 9036990d462e09366f7297a2d1da6582c3e6b1d3 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Wed, 5 Nov 2008 16:05:44 -0500
Subject: ftrace: restructure tracing start/stop infrastructure

Impact: change where tracing is started up and stopped

Currently, when a new tracer is selected via echo'ing a tracer name into
the current_tracer file, the startup is only done if tracing_enabled is
set to one. If tracing_enabled is changed to zero (by echo'ing 0 into
the tracing_enabled file) a full shutdown is performed.

The full startup and shutdown of a tracer can be expensive and the
user can lose out traces when echo'ing in 0 to the tracing_enabled file,
because the process takes too long. There can also be places that
the user would like to start and stop the tracer several times and
doing the full startup and shutdown of a tracer might be too expensive.

This patch performs the full startup and shutdown when a tracer is
selected. It also adds a way to do a quick start or stop of a tracer.
The quick version is just a flag that prevents the tracing from
taking place, but the overhead of the code is still there.

For example, the startup of a tracer may enable tracepoints, or enable
the function tracer.  The stop and start will just set a flag to
have the tracer ignore the calls when the tracepoint or function trace
is called.  The overhead of the tracer may still be present when
the tracer is stopped, but no tracing will occur. Setting the tracer
to the 'nop' tracer (or any other tracer) will perform the shutdown
of the tracer which will disable the tracepoint or disable the
function tracer.

The tracing_enabled file will simply start or stop tracing.

This change is all internal. The end result for the user should be the same
as before. If tracing_enabled is not set, no trace will happen.
If tracing_enabled is set, then the trace will happen. The tracing_enabled
variable is static between tracers. Enabling  tracing_enabled and
going to another tracer will keep tracing_enabled enabled. Same
is true with disabling tracing_enabled.

This patch will now provide a fast start/stop method to the users
for enabling or disabling tracing.

Note: There were two methods to the struct tracer that were never
 used: The methods start and stop. These were to be used as a hook
 to the reading of the trace output, but ended up not being
 necessary. These two methods are now used to enable the start
 and stop of each tracer, in case the tracer needs to do more than
 just not write into the buffer. For example, the irqsoff tracer
 must stop recording max latencies when tracing is stopped.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace.c              | 64 +++++++++++++++++----------------------
 kernel/trace/trace.h              |  5 +--
 kernel/trace/trace_functions.c    |  6 ++++
 kernel/trace/trace_irqsoff.c      | 41 ++++++++++++++++++++++---
 kernel/trace/trace_sched_switch.c | 13 ++++++++
 kernel/trace/trace_sched_wakeup.c | 39 +++++++++++++++++++++---
 6 files changed, 120 insertions(+), 48 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 113aea9447ec..ff1e9ed9b587 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -150,6 +150,19 @@ static DEFINE_PER_CPU(struct trace_array_cpu, max_data);
 /* tracer_enabled is used to toggle activation of a tracer */
 static int			tracer_enabled = 1;
 
+/**
+ * tracing_is_enabled - return tracer_enabled status
+ *
+ * This function is used by other tracers to know the status
+ * of the tracer_enabled flag.  Tracers may use this function
+ * to know if it should enable their features when starting
+ * up. See irqsoff tracer for an example (start_irqsoff_tracer).
+ */
+int tracing_is_enabled(void)
+{
+	return tracer_enabled;
+}
+
 /* function tracing enabled */
 int				ftrace_function_enabled;
 
@@ -1041,8 +1054,7 @@ void tracing_start_function_trace(void)
 		trace_ops.func = function_trace_call;
 
 	register_ftrace_function(&trace_ops);
-	if (tracer_enabled)
-		ftrace_function_enabled = 1;
+	ftrace_function_enabled = 1;
 }
 
 void tracing_stop_function_trace(void)
@@ -1189,10 +1201,6 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 
 	atomic_inc(&trace_record_cmdline_disabled);
 
-	/* let the tracer grab locks here if needed */
-	if (current_trace->start)
-		current_trace->start(iter);
-
 	if (*pos != iter->pos) {
 		iter->ent = NULL;
 		iter->cpu = 0;
@@ -1219,14 +1227,7 @@ static void *s_start(struct seq_file *m, loff_t *pos)
 
 static void s_stop(struct seq_file *m, void *p)
 {
-	struct trace_iterator *iter = m->private;
-
 	atomic_dec(&trace_record_cmdline_disabled);
-
-	/* let the tracer release locks here if needed */
-	if (current_trace && current_trace == iter->trace && iter->trace->stop)
-		iter->trace->stop(iter);
-
 	mutex_unlock(&trace_types_lock);
 }
 
@@ -2056,10 +2057,7 @@ __tracing_open(struct inode *inode, struct file *file, int *ret)
 	m->private = iter;
 
 	/* stop the trace while dumping */
-	if (iter->tr->ctrl) {
-		tracer_enabled = 0;
-		ftrace_function_enabled = 0;
-	}
+	tracing_stop();
 
 	if (iter->trace && iter->trace->open)
 			iter->trace->open(iter);
@@ -2104,14 +2102,7 @@ int tracing_release(struct inode *inode, struct file *file)
 		iter->trace->close(iter);
 
 	/* reenable tracing if it was previously enabled */
-	if (iter->tr->ctrl) {
-		tracer_enabled = 1;
-		/*
-		 * It is safe to enable function tracing even if it
-		 * isn't used
-		 */
-		ftrace_function_enabled = 1;
-	}
+	tracing_start();
 	mutex_unlock(&trace_types_lock);
 
 	seq_release(inode, file);
@@ -2449,11 +2440,10 @@ static ssize_t
 tracing_ctrl_read(struct file *filp, char __user *ubuf,
 		  size_t cnt, loff_t *ppos)
 {
-	struct trace_array *tr = filp->private_data;
 	char buf[64];
 	int r;
 
-	r = sprintf(buf, "%ld\n", tr->ctrl);
+	r = sprintf(buf, "%u\n", tracer_enabled);
 	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
 }
 
@@ -2481,16 +2471,18 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf,
 	val = !!val;
 
 	mutex_lock(&trace_types_lock);
-	if (tr->ctrl ^ val) {
-		if (val)
+	if (tracer_enabled ^ val) {
+		if (val) {
 			tracer_enabled = 1;
-		else
+			if (current_trace->start)
+				current_trace->start(tr);
+			tracing_start();
+		} else {
 			tracer_enabled = 0;
-
-		tr->ctrl = val;
-
-		if (current_trace && current_trace->ctrl_update)
-			current_trace->ctrl_update(tr);
+			tracing_stop();
+			if (current_trace->stop)
+				current_trace->stop(tr);
+		}
 	}
 	mutex_unlock(&trace_types_lock);
 
@@ -3372,7 +3364,7 @@ __init static int tracer_alloc_buffers(void)
 #endif
 
 	/* All seems OK, enable tracing */
-	global_trace.ctrl = tracer_enabled;
+	global_trace.ctrl = 1;
 	tracing_disabled = 0;
 
 	atomic_notifier_chain_register(&panic_notifier_list,
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index cc14a6bc1094..3422489fad5e 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -237,11 +237,11 @@ struct tracer {
 	const char		*name;
 	void			(*init)(struct trace_array *tr);
 	void			(*reset)(struct trace_array *tr);
+	void			(*start)(struct trace_array *tr);
+	void			(*stop)(struct trace_array *tr);
 	void			(*open)(struct trace_iterator *iter);
 	void			(*pipe_open)(struct trace_iterator *iter);
 	void			(*close)(struct trace_iterator *iter);
-	void			(*start)(struct trace_iterator *iter);
-	void			(*stop)(struct trace_iterator *iter);
 	ssize_t			(*read)(struct trace_iterator *iter,
 					struct file *filp, char __user *ubuf,
 					size_t cnt, loff_t *ppos);
@@ -282,6 +282,7 @@ struct trace_iterator {
 	long			idx;
 };
 
+int tracing_is_enabled(void);
 void trace_wake_up(void);
 void tracing_reset(struct trace_array *tr, int cpu);
 int tracing_open_generic(struct inode *inode, struct file *filp);
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 0f85a64003d3..9f1b0de71284 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -62,11 +62,17 @@ static void function_trace_ctrl_update(struct trace_array *tr)
 		stop_function_trace(tr);
 }
 
+static void function_trace_start(struct trace_array *tr)
+{
+	function_reset(tr);
+}
+
 static struct tracer function_trace __read_mostly =
 {
 	.name	     = "function",
 	.init	     = function_trace_init,
 	.reset	     = function_trace_reset,
+	.start	     = function_trace_start,
 	.ctrl_update = function_trace_ctrl_update,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_function,
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 9c74071c10e0..a87a20fa3fc6 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -353,15 +353,28 @@ void trace_preempt_off(unsigned long a0, unsigned long a1)
 }
 #endif /* CONFIG_PREEMPT_TRACER */
 
+/*
+ * save_tracer_enabled is used to save the state of the tracer_enabled
+ * variable when we disable it when we open a trace output file.
+ */
+static int save_tracer_enabled;
+
 static void start_irqsoff_tracer(struct trace_array *tr)
 {
 	register_ftrace_function(&trace_ops);
-	tracer_enabled = 1;
+	if (tracing_is_enabled()) {
+		tracer_enabled = 1;
+		save_tracer_enabled = 1;
+	} else {
+		tracer_enabled = 0;
+		save_tracer_enabled = 0;
+	}
 }
 
 static void stop_irqsoff_tracer(struct trace_array *tr)
 {
 	tracer_enabled = 0;
+	save_tracer_enabled = 0;
 	unregister_ftrace_function(&trace_ops);
 }
 
@@ -389,17 +402,29 @@ static void irqsoff_tracer_ctrl_update(struct trace_array *tr)
 		stop_irqsoff_tracer(tr);
 }
 
+static void irqsoff_tracer_start(struct trace_array *tr)
+{
+	irqsoff_tracer_reset(tr);
+	tracer_enabled = 1;
+	save_tracer_enabled = 1;
+}
+
+static void irqsoff_tracer_stop(struct trace_array *tr)
+{
+	tracer_enabled = 0;
+	save_tracer_enabled = 0;
+}
+
 static void irqsoff_tracer_open(struct trace_iterator *iter)
 {
 	/* stop the trace while dumping */
-	if (iter->tr->ctrl)
-		stop_irqsoff_tracer(iter->tr);
+	tracer_enabled = 0;
 }
 
 static void irqsoff_tracer_close(struct trace_iterator *iter)
 {
-	if (iter->tr->ctrl)
-		start_irqsoff_tracer(iter->tr);
+	/* restart tracing */
+	tracer_enabled = save_tracer_enabled;
 }
 
 #ifdef CONFIG_IRQSOFF_TRACER
@@ -414,6 +439,8 @@ static struct tracer irqsoff_tracer __read_mostly =
 	.name		= "irqsoff",
 	.init		= irqsoff_tracer_init,
 	.reset		= irqsoff_tracer_reset,
+	.start		= irqsoff_tracer_start,
+	.stop		= irqsoff_tracer_stop,
 	.open		= irqsoff_tracer_open,
 	.close		= irqsoff_tracer_close,
 	.ctrl_update	= irqsoff_tracer_ctrl_update,
@@ -440,6 +467,8 @@ static struct tracer preemptoff_tracer __read_mostly =
 	.name		= "preemptoff",
 	.init		= preemptoff_tracer_init,
 	.reset		= irqsoff_tracer_reset,
+	.start		= irqsoff_tracer_start,
+	.stop		= irqsoff_tracer_stop,
 	.open		= irqsoff_tracer_open,
 	.close		= irqsoff_tracer_close,
 	.ctrl_update	= irqsoff_tracer_ctrl_update,
@@ -468,6 +497,8 @@ static struct tracer preemptirqsoff_tracer __read_mostly =
 	.name		= "preemptirqsoff",
 	.init		= preemptirqsoff_tracer_init,
 	.reset		= irqsoff_tracer_reset,
+	.start		= irqsoff_tracer_start,
+	.stop		= irqsoff_tracer_stop,
 	.open		= irqsoff_tracer_open,
 	.close		= irqsoff_tracer_close,
 	.ctrl_update	= irqsoff_tracer_ctrl_update,
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 888944d3409d..91c699be8c87 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -186,11 +186,24 @@ static void sched_switch_trace_ctrl_update(struct trace_array *tr)
 		stop_sched_trace(tr);
 }
 
+static void sched_switch_trace_start(struct trace_array *tr)
+{
+	sched_switch_reset(tr);
+	tracing_start_sched_switch();
+}
+
+static void sched_switch_trace_stop(struct trace_array *tr)
+{
+	tracing_stop_sched_switch();
+}
+
 struct tracer sched_switch_trace __read_mostly =
 {
 	.name		= "sched_switch",
 	.init		= sched_switch_trace_init,
 	.reset		= sched_switch_trace_reset,
+	.start		= sched_switch_trace_start,
+	.stop		= sched_switch_trace_stop,
 	.ctrl_update	= sched_switch_trace_ctrl_update,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_sched_switch,
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 7bc4abf6fca8..240577bc8ba5 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -262,6 +262,12 @@ out:
 	atomic_dec(&wakeup_trace->data[cpu]->disabled);
 }
 
+/*
+ * save_tracer_enabled is used to save the state of the tracer_enabled
+ * variable when we disable it when we open a trace output file.
+ */
+static int save_tracer_enabled;
+
 static void start_wakeup_tracer(struct trace_array *tr)
 {
 	int ret;
@@ -300,7 +306,13 @@ static void start_wakeup_tracer(struct trace_array *tr)
 
 	register_ftrace_function(&trace_ops);
 
-	tracer_enabled = 1;
+	if (tracing_is_enabled()) {
+		tracer_enabled = 1;
+		save_tracer_enabled = 1;
+	} else {
+		tracer_enabled = 0;
+		save_tracer_enabled = 0;
+	}
 
 	return;
 fail_deprobe_wake_new:
@@ -312,6 +324,7 @@ fail_deprobe:
 static void stop_wakeup_tracer(struct trace_array *tr)
 {
 	tracer_enabled = 0;
+	save_tracer_enabled = 0;
 	unregister_ftrace_function(&trace_ops);
 	unregister_trace_sched_switch(probe_wakeup_sched_switch);
 	unregister_trace_sched_wakeup_new(probe_wakeup);
@@ -343,18 +356,32 @@ static void wakeup_tracer_ctrl_update(struct trace_array *tr)
 		stop_wakeup_tracer(tr);
 }
 
+static void wakeup_tracer_start(struct trace_array *tr)
+{
+	wakeup_reset(tr);
+	tracer_enabled = 1;
+	save_tracer_enabled = 1;
+}
+
+static void wakeup_tracer_stop(struct trace_array *tr)
+{
+	tracer_enabled = 0;
+	save_tracer_enabled = 0;
+}
+
 static void wakeup_tracer_open(struct trace_iterator *iter)
 {
 	/* stop the trace while dumping */
-	if (iter->tr->ctrl)
-		stop_wakeup_tracer(iter->tr);
+	tracer_enabled = 0;
 }
 
 static void wakeup_tracer_close(struct trace_iterator *iter)
 {
 	/* forget about any processes we were recording */
-	if (iter->tr->ctrl)
-		start_wakeup_tracer(iter->tr);
+	if (save_tracer_enabled) {
+		wakeup_reset(iter->tr);
+		tracer_enabled = 1;
+	}
 }
 
 static struct tracer wakeup_tracer __read_mostly =
@@ -362,6 +389,8 @@ static struct tracer wakeup_tracer __read_mostly =
 	.name		= "wakeup",
 	.init		= wakeup_tracer_init,
 	.reset		= wakeup_tracer_reset,
+	.start		= wakeup_tracer_start,
+	.stop		= wakeup_tracer_stop,
 	.open		= wakeup_tracer_open,
 	.close		= wakeup_tracer_close,
 	.ctrl_update	= wakeup_tracer_ctrl_update,
-- 
cgit v1.2.3-59-g8ed1b


From 75f5c47da386445ba0c5a8b7e3ca0c906e763369 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Fri, 7 Nov 2008 22:36:02 -0500
Subject: ftrace: fix boot trace sched startup

Impact: boot tracer startup modified

The boot tracer calls into some of the schedule tracing private functions
that should not be exported. This patch cleans it up, and makes
way for further changes in the ftrace infrastructure.

This patch adds a api to assign a tracer array to the schedule
context switch tracer.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace.h              |  2 +-
 kernel/trace/trace_boot.c         |  9 +++++++--
 kernel/trace/trace_sched_switch.c | 15 ++++++++++++++-
 3 files changed, 22 insertions(+), 4 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 3422489fad5e..db12e16137e1 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -49,7 +49,6 @@ struct ftrace_entry {
 	unsigned long		parent_ip;
 };
 extern struct tracer boot_tracer;
-extern struct tracer sched_switch_trace; /* Used by the boot tracer */
 
 /*
  * Context switch trace entry - which task (and prio) we switched from/to:
@@ -325,6 +324,7 @@ void trace_function(struct trace_array *tr,
 
 void tracing_start_cmdline_record(void);
 void tracing_stop_cmdline_record(void);
+void tracing_cmdline_assign_trace(struct trace_array *tr);
 int register_tracer(struct tracer *type);
 void unregister_tracer(struct tracer *type);
 
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index bd5046c9deb7..662cb9198906 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -39,7 +39,12 @@ void disable_boot_trace(void)
 
 static void reset_boot_trace(struct trace_array *tr)
 {
-	sched_switch_trace.reset(tr);
+	int cpu;
+
+	tr->time_start = ftrace_now(tr->cpu);
+
+	for_each_online_cpu(cpu)
+		tracing_reset(tr, cpu);
 }
 
 static void boot_trace_init(struct trace_array *tr)
@@ -50,7 +55,7 @@ static void boot_trace_init(struct trace_array *tr)
 	for_each_cpu_mask(cpu, cpu_possible_map)
 		tracing_reset(tr, cpu);
 
-	sched_switch_trace.init(tr);
+	tracing_cmdline_assign_trace(tr);
 }
 
 static void boot_trace_ctrl_update(struct trace_array *tr)
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 91c699be8c87..fbf05df7134d 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -152,6 +152,19 @@ void tracing_stop_cmdline_record(void)
 	tracing_stop_sched_switch();
 }
 
+/**
+ * tracing_cmdline_assign_trace - assign a trace array for ctx switch
+ * @tr: trace array pointer to assign
+ *
+ * Some tracers might want to record the context switches in their
+ * trace. This function lets those tracers assign the trace array
+ * to use.
+ */
+void tracing_cmdline_assign_trace(struct trace_array *tr)
+{
+	ctx_trace = tr;
+}
+
 static void start_sched_trace(struct trace_array *tr)
 {
 	sched_switch_reset(tr);
@@ -197,7 +210,7 @@ static void sched_switch_trace_stop(struct trace_array *tr)
 	tracing_stop_sched_switch();
 }
 
-struct tracer sched_switch_trace __read_mostly =
+static struct tracer sched_switch_trace __read_mostly =
 {
 	.name		= "sched_switch",
 	.init		= sched_switch_trace_init,
-- 
cgit v1.2.3-59-g8ed1b


From e168e0516e476070faa9e8e7b23dfcba79b76d82 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Fri, 7 Nov 2008 22:36:02 -0500
Subject: ftrace: fix sched_switch API

Impact: fix for sched_switch that broke dynamic ftrace startup

The commit: tracing/fastboot: use sched switch tracer from boot tracer
broke the API of the sched_switch trace. The use of the
tracing_start/stop_cmdline record is for only recording the cmdline,
NOT recording the schedule switches themselves.

Seeing that the boot tracer broke the API to do something that it
wanted, this patch adds a new interface for the API while
puting back the original interface of the old API.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace.h              |  4 +++-
 kernel/trace/trace_boot.c         |  6 ++---
 kernel/trace/trace_sched_switch.c | 50 +++++++++++++++++++++++++++++++--------
 3 files changed, 46 insertions(+), 14 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index db12e16137e1..25abfc45f081 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -324,7 +324,9 @@ void trace_function(struct trace_array *tr,
 
 void tracing_start_cmdline_record(void);
 void tracing_stop_cmdline_record(void);
-void tracing_cmdline_assign_trace(struct trace_array *tr);
+void tracing_sched_switch_assign_trace(struct trace_array *tr);
+void tracing_stop_sched_switch_record(void);
+void tracing_start_sched_switch_record(void);
 int register_tracer(struct tracer *type);
 void unregister_tracer(struct tracer *type);
 
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 662cb9198906..0203c1054012 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -28,13 +28,13 @@ void start_boot_trace(void)
 void enable_boot_trace(void)
 {
 	if (pre_initcalls_finished)
-		tracing_start_cmdline_record();
+		tracing_start_sched_switch_record();
 }
 
 void disable_boot_trace(void)
 {
 	if (pre_initcalls_finished)
-		tracing_stop_cmdline_record();
+		tracing_stop_sched_switch_record();
 }
 
 static void reset_boot_trace(struct trace_array *tr)
@@ -55,7 +55,7 @@ static void boot_trace_init(struct trace_array *tr)
 	for_each_cpu_mask(cpu, cpu_possible_map)
 		tracing_reset(tr, cpu);
 
-	tracing_cmdline_assign_trace(tr);
+	tracing_sched_switch_assign_trace(tr);
 }
 
 static void boot_trace_ctrl_update(struct trace_array *tr)
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index fbf05df7134d..79410db64d6f 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -125,20 +125,16 @@ static void tracing_sched_unregister(void)
 static void tracing_start_sched_switch(void)
 {
 	mutex_lock(&sched_register_mutex);
-	if (!(sched_ref++)) {
-		tracer_enabled = 1;
+	if (!(sched_ref++))
 		tracing_sched_register();
-	}
 	mutex_unlock(&sched_register_mutex);
 }
 
 static void tracing_stop_sched_switch(void)
 {
 	mutex_lock(&sched_register_mutex);
-	if (!(--sched_ref)) {
+	if (!(--sched_ref))
 		tracing_sched_unregister();
-		tracer_enabled = 0;
-	}
 	mutex_unlock(&sched_register_mutex);
 }
 
@@ -153,14 +149,48 @@ void tracing_stop_cmdline_record(void)
 }
 
 /**
- * tracing_cmdline_assign_trace - assign a trace array for ctx switch
+ * tracing_start_sched_switch_record - start tracing context switches
+ *
+ * Turns on context switch tracing for a tracer.
+ */
+void tracing_start_sched_switch_record(void)
+{
+	if (unlikely(!ctx_trace)) {
+		WARN_ON(1);
+		return;
+	}
+
+	tracing_start_sched_switch();
+
+	mutex_lock(&sched_register_mutex);
+	tracer_enabled++;
+	mutex_unlock(&sched_register_mutex);
+}
+
+/**
+ * tracing_stop_sched_switch_record - start tracing context switches
+ *
+ * Turns off context switch tracing for a tracer.
+ */
+void tracing_stop_sched_switch_record(void)
+{
+	mutex_lock(&sched_register_mutex);
+	tracer_enabled--;
+	WARN_ON(tracer_enabled < 0);
+	mutex_unlock(&sched_register_mutex);
+
+	tracing_stop_sched_switch();
+}
+
+/**
+ * tracing_sched_switch_assign_trace - assign a trace array for ctx switch
  * @tr: trace array pointer to assign
  *
  * Some tracers might want to record the context switches in their
  * trace. This function lets those tracers assign the trace array
  * to use.
  */
-void tracing_cmdline_assign_trace(struct trace_array *tr)
+void tracing_sched_switch_assign_trace(struct trace_array *tr)
 {
 	ctx_trace = tr;
 }
@@ -168,12 +198,12 @@ void tracing_cmdline_assign_trace(struct trace_array *tr)
 static void start_sched_trace(struct trace_array *tr)
 {
 	sched_switch_reset(tr);
-	tracing_start_cmdline_record();
+	tracing_start_sched_switch_record();
 }
 
 static void stop_sched_trace(struct trace_array *tr)
 {
-	tracing_stop_cmdline_record();
+	tracing_stop_sched_switch_record();
 }
 
 static void sched_switch_trace_init(struct trace_array *tr)
-- 
cgit v1.2.3-59-g8ed1b


From bbf5b1a0cecb56de6236db8b01c5bfb7ab8ba8b2 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Fri, 7 Nov 2008 22:36:02 -0500
Subject: ftrace: remove ctrl_update method

Impact: Remove the ctrl_update tracer method

With the new quick start/stop method of tracing, the ctrl_update
method is out of date.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace.c              |  2 --
 kernel/trace/trace.h              |  1 -
 kernel/trace/trace_boot.c         |  9 --------
 kernel/trace/trace_functions.c    |  9 --------
 kernel/trace/trace_irqsoff.c      | 11 ---------
 kernel/trace/trace_mmiotrace.c    | 11 +++------
 kernel/trace/trace_nop.c          | 10 --------
 kernel/trace/trace_sched_switch.c | 10 --------
 kernel/trace/trace_sched_wakeup.c |  9 --------
 kernel/trace/trace_selftest.c     | 48 +++++++++++++++++++++------------------
 kernel/trace/trace_sysprof.c      | 10 --------
 11 files changed, 29 insertions(+), 101 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index dbbdacfaaf9e..9e83188172a1 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3357,8 +3357,6 @@ __init static int tracer_alloc_buffers(void)
 
 	register_tracer(&nop_trace);
 #ifdef CONFIG_BOOT_TRACER
-	/* We don't want to launch sched_switch tracer yet */
-	global_trace.ctrl = 0;
 	register_tracer(&boot_tracer);
 	current_trace = &boot_tracer;
 	current_trace->init(&global_trace);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 25abfc45f081..e481edaae1c4 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -244,7 +244,6 @@ struct tracer {
 	ssize_t			(*read)(struct trace_iterator *iter,
 					struct file *filp, char __user *ubuf,
 					size_t cnt, loff_t *ppos);
-	void			(*ctrl_update)(struct trace_array *tr);
 #ifdef CONFIG_FTRACE_STARTUP_TEST
 	int			(*selftest)(struct tracer *trace,
 					    struct trace_array *tr);
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 0203c1054012..8f71915e8bb4 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -58,14 +58,6 @@ static void boot_trace_init(struct trace_array *tr)
 	tracing_sched_switch_assign_trace(tr);
 }
 
-static void boot_trace_ctrl_update(struct trace_array *tr)
-{
-	if (tr->ctrl)
-		enable_boot_trace();
-	else
-		disable_boot_trace();
-}
-
 static enum print_line_t initcall_print_line(struct trace_iterator *iter)
 {
 	int ret;
@@ -102,7 +94,6 @@ struct tracer boot_tracer __read_mostly =
 	.name		= "initcall",
 	.init		= boot_trace_init,
 	.reset		= reset_boot_trace,
-	.ctrl_update	= boot_trace_ctrl_update,
 	.print_line	= initcall_print_line,
 };
 
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 9f1b0de71284..e980b872bef5 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -54,14 +54,6 @@ static void function_trace_reset(struct trace_array *tr)
 		stop_function_trace(tr);
 }
 
-static void function_trace_ctrl_update(struct trace_array *tr)
-{
-	if (tr->ctrl)
-		start_function_trace(tr);
-	else
-		stop_function_trace(tr);
-}
-
 static void function_trace_start(struct trace_array *tr)
 {
 	function_reset(tr);
@@ -73,7 +65,6 @@ static struct tracer function_trace __read_mostly =
 	.init	     = function_trace_init,
 	.reset	     = function_trace_reset,
 	.start	     = function_trace_start,
-	.ctrl_update = function_trace_ctrl_update,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_function,
 #endif
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index 3509086cdc4c..ffdf592a54e3 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -394,14 +394,6 @@ static void irqsoff_tracer_reset(struct trace_array *tr)
 		stop_irqsoff_tracer(tr);
 }
 
-static void irqsoff_tracer_ctrl_update(struct trace_array *tr)
-{
-	if (tr->ctrl)
-		start_irqsoff_tracer(tr);
-	else
-		stop_irqsoff_tracer(tr);
-}
-
 static void irqsoff_tracer_start(struct trace_array *tr)
 {
 	tracer_enabled = 1;
@@ -442,7 +434,6 @@ static struct tracer irqsoff_tracer __read_mostly =
 	.stop		= irqsoff_tracer_stop,
 	.open		= irqsoff_tracer_open,
 	.close		= irqsoff_tracer_close,
-	.ctrl_update	= irqsoff_tracer_ctrl_update,
 	.print_max	= 1,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_irqsoff,
@@ -470,7 +461,6 @@ static struct tracer preemptoff_tracer __read_mostly =
 	.stop		= irqsoff_tracer_stop,
 	.open		= irqsoff_tracer_open,
 	.close		= irqsoff_tracer_close,
-	.ctrl_update	= irqsoff_tracer_ctrl_update,
 	.print_max	= 1,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_preemptoff,
@@ -500,7 +490,6 @@ static struct tracer preemptirqsoff_tracer __read_mostly =
 	.stop		= irqsoff_tracer_stop,
 	.open		= irqsoff_tracer_open,
 	.close		= irqsoff_tracer_close,
-	.ctrl_update	= irqsoff_tracer_ctrl_update,
 	.print_max	= 1,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_preemptirqsoff,
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index f28484618ff0..fa9354e78b57 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -49,15 +49,10 @@ static void mmio_trace_reset(struct trace_array *tr)
 	mmio_trace_array = NULL;
 }
 
-static void mmio_trace_ctrl_update(struct trace_array *tr)
+static void mmio_trace_start(struct trace_array *tr)
 {
 	pr_debug("in %s\n", __func__);
-	if (tr->ctrl) {
-		mmio_reset_data(tr);
-		enable_mmiotrace();
-	} else {
-		disable_mmiotrace();
-	}
+	mmio_reset_data(tr);
 }
 
 static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev)
@@ -298,10 +293,10 @@ static struct tracer mmio_tracer __read_mostly =
 	.name		= "mmiotrace",
 	.init		= mmio_trace_init,
 	.reset		= mmio_trace_reset,
+	.start		= mmio_trace_start,
 	.pipe_open	= mmio_pipe_open,
 	.close		= mmio_close,
 	.read		= mmio_read,
-	.ctrl_update	= mmio_trace_ctrl_update,
 	.print_line	= mmio_print_line,
 };
 
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index 4592b4862515..e3c5fbfcdd36 100644
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -42,21 +42,11 @@ static void nop_trace_reset(struct trace_array *tr)
 		stop_nop_trace(tr);
 }
 
-static void nop_trace_ctrl_update(struct trace_array *tr)
-{
-	/* When starting a new trace, reset the buffers */
-	if (tr->ctrl)
-		start_nop_trace(tr);
-	else
-		stop_nop_trace(tr);
-}
-
 struct tracer nop_trace __read_mostly =
 {
 	.name		= "nop",
 	.init		= nop_trace_init,
 	.reset		= nop_trace_reset,
-	.ctrl_update	= nop_trace_ctrl_update,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest	= trace_selftest_startup_nop,
 #endif
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 79410db64d6f..7b73fd11e4aa 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -220,15 +220,6 @@ static void sched_switch_trace_reset(struct trace_array *tr)
 		stop_sched_trace(tr);
 }
 
-static void sched_switch_trace_ctrl_update(struct trace_array *tr)
-{
-	/* When starting a new trace, reset the buffers */
-	if (tr->ctrl)
-		start_sched_trace(tr);
-	else
-		stop_sched_trace(tr);
-}
-
 static void sched_switch_trace_start(struct trace_array *tr)
 {
 	sched_switch_reset(tr);
@@ -247,7 +238,6 @@ static struct tracer sched_switch_trace __read_mostly =
 	.reset		= sched_switch_trace_reset,
 	.start		= sched_switch_trace_start,
 	.stop		= sched_switch_trace_stop,
-	.ctrl_update	= sched_switch_trace_ctrl_update,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_sched_switch,
 #endif
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 240577bc8ba5..23e54d4e4d92 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -348,14 +348,6 @@ static void wakeup_tracer_reset(struct trace_array *tr)
 	}
 }
 
-static void wakeup_tracer_ctrl_update(struct trace_array *tr)
-{
-	if (tr->ctrl)
-		start_wakeup_tracer(tr);
-	else
-		stop_wakeup_tracer(tr);
-}
-
 static void wakeup_tracer_start(struct trace_array *tr)
 {
 	wakeup_reset(tr);
@@ -393,7 +385,6 @@ static struct tracer wakeup_tracer __read_mostly =
 	.stop		= wakeup_tracer_stop,
 	.open		= wakeup_tracer_open,
 	.close		= wakeup_tracer_close,
-	.ctrl_update	= wakeup_tracer_ctrl_update,
 	.print_max	= 1,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_wakeup,
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 90bc752a7580..746934340474 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -134,13 +134,13 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 	msleep(100);
 
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	ftrace_enabled = 0;
 
 	/* check the trace buffer */
 	ret = trace_test_buffer(tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	/* we should only have one item */
 	if (!ret && count != 1) {
@@ -148,6 +148,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 		ret = -1;
 		goto out;
 	}
+
  out:
 	ftrace_enabled = save_ftrace_enabled;
 	tracer_enabled = save_tracer_enabled;
@@ -185,13 +186,13 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	ftrace_enabled = 0;
 
 	/* check the trace buffer */
 	ret = trace_test_buffer(tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
@@ -232,13 +233,13 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
 	udelay(100);
 	local_irq_enable();
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check both trace buffers */
 	ret = trace_test_buffer(tr, NULL);
 	if (!ret)
 		ret = trace_test_buffer(&max_tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
@@ -269,13 +270,13 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
 	udelay(100);
 	preempt_enable();
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check both trace buffers */
 	ret = trace_test_buffer(tr, NULL);
 	if (!ret)
 		ret = trace_test_buffer(&max_tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
@@ -312,27 +313,30 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	local_irq_enable();
 
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check both trace buffers */
 	ret = trace_test_buffer(tr, NULL);
-	if (ret)
+	if (ret) {
+		tracing_start();
 		goto out;
+	}
 
 	ret = trace_test_buffer(&max_tr, &count);
-	if (ret)
+	if (ret) {
+		tracing_start();
 		goto out;
+	}
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
 		ret = -1;
+		tracing_start();
 		goto out;
 	}
 
 	/* do the test by disabling interrupts first this time */
 	tracing_max_latency = 0;
-	tr->ctrl = 1;
-	trace->ctrl_update(tr);
+	tracing_start();
 	preempt_disable();
 	local_irq_disable();
 	udelay(100);
@@ -341,8 +345,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	local_irq_enable();
 
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check both trace buffers */
 	ret = trace_test_buffer(tr, NULL);
 	if (ret)
@@ -358,6 +361,7 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 
  out:
 	trace->reset(tr);
+	tracing_start();
 	tracing_max_latency = save_max;
 
 	return ret;
@@ -448,8 +452,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 	msleep(100);
 
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check both trace buffers */
 	ret = trace_test_buffer(tr, NULL);
 	if (!ret)
@@ -457,6 +460,7 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 
 
 	trace->reset(tr);
+	tracing_start();
 
 	tracing_max_latency = save_max;
 
@@ -485,11 +489,11 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check the trace buffer */
 	ret = trace_test_buffer(tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	if (!ret && !count) {
 		printk(KERN_CONT ".. no entries found ..");
@@ -513,11 +517,11 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
 	/* stop the tracing. */
-	tr->ctrl = 0;
-	trace->ctrl_update(tr);
+	tracing_stop();
 	/* check the trace buffer */
 	ret = trace_test_buffer(tr, &count);
 	trace->reset(tr);
+	tracing_start();
 
 	return ret;
 }
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index 9587d3bcba55..8097430edff9 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -275,21 +275,11 @@ static void stack_trace_reset(struct trace_array *tr)
 		stop_stack_trace(tr);
 }
 
-static void stack_trace_ctrl_update(struct trace_array *tr)
-{
-	/* When starting a new trace, reset the buffers */
-	if (tr->ctrl)
-		start_stack_trace(tr);
-	else
-		stop_stack_trace(tr);
-}
-
 static struct tracer stack_trace __read_mostly =
 {
 	.name		= "sysprof",
 	.init		= stack_trace_init,
 	.reset		= stack_trace_reset,
-	.ctrl_update	= stack_trace_ctrl_update,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_sysprof,
 #endif
-- 
cgit v1.2.3-59-g8ed1b


From c76f06945be50564f925799ddfb6235ee4c26aa0 Mon Sep 17 00:00:00 2001
From: Steven Rostedt <srostedt@redhat.com>
Date: Fri, 7 Nov 2008 22:36:02 -0500
Subject: ftrace: remove trace array ctrl

Impact: remove obsolete variable in trace_array structure

With the new start / stop method of ftrace, the ctrl variable
in the trace_array structure is now obsolete. Remove it.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace.c              | 20 +++++---------------
 kernel/trace/trace.h              |  1 -
 kernel/trace/trace_functions.c    |  6 ++----
 kernel/trace/trace_irqsoff.c      |  7 ++-----
 kernel/trace/trace_mmiotrace.c    | 11 +++++------
 kernel/trace/trace_nop.c          |  6 ++----
 kernel/trace/trace_sched_switch.c |  6 ++----
 kernel/trace/trace_sched_wakeup.c | 12 ++++--------
 kernel/trace/trace_selftest.c     |  8 --------
 kernel/trace/trace_sysprof.c      |  6 ++----
 10 files changed, 24 insertions(+), 59 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 9e83188172a1..58435415b366 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -537,7 +537,6 @@ int register_tracer(struct tracer *type)
 	if (type->selftest) {
 		struct tracer *saved_tracer = current_trace;
 		struct trace_array *tr = &global_trace;
-		int saved_ctrl = tr->ctrl;
 		int i;
 		/*
 		 * Run a selftest on this tracer.
@@ -550,13 +549,11 @@ int register_tracer(struct tracer *type)
 			tracing_reset(tr, i);
 		}
 		current_trace = type;
-		tr->ctrl = 0;
 		/* the test is responsible for initializing and enabling */
 		pr_info("Testing tracer %s: ", type->name);
 		ret = type->selftest(type, tr);
 		/* the test is responsible for resetting too */
 		current_trace = saved_tracer;
-		tr->ctrl = saved_ctrl;
 		if (ret) {
 			printk(KERN_CONT "FAILED!\n");
 			goto out;
@@ -966,7 +963,7 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3)
 	int cpu;
 	int pc;
 
-	if (tracing_disabled || !tr->ctrl)
+	if (tracing_disabled)
 		return;
 
 	pc = preempt_count();
@@ -2820,7 +2817,6 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 	unsigned long val;
 	char buf[64];
 	int ret;
-	struct trace_array *tr = filp->private_data;
 
 	if (cnt >= sizeof(buf))
 		return -EINVAL;
@@ -2840,12 +2836,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 
 	mutex_lock(&trace_types_lock);
 
-	if (tr->ctrl) {
-		cnt = -EBUSY;
-		pr_info("ftrace: please disable tracing"
-			" before modifying buffer size\n");
-		goto out;
-	}
+	tracing_stop();
 
 	if (val != global_trace.entries) {
 		ret = ring_buffer_resize(global_trace.buffer, val);
@@ -2878,6 +2869,7 @@ tracing_entries_write(struct file *filp, const char __user *ubuf,
 	if (tracing_disabled)
 		cnt = -ENOMEM;
  out:
+	tracing_start();
 	max_tr.entries = global_trace.entries;
 	mutex_unlock(&trace_types_lock);
 
@@ -2900,9 +2892,8 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 {
 	char *buf;
 	char *end;
-	struct trace_array *tr = &global_trace;
 
-	if (!tr->ctrl || tracing_disabled)
+	if (tracing_disabled)
 		return -EINVAL;
 
 	if (cnt > TRACE_BUF_SIZE)
@@ -3131,7 +3122,7 @@ int trace_vprintk(unsigned long ip, const char *fmt, va_list args)
 	unsigned long flags, irq_flags;
 	int cpu, len = 0, size, pc;
 
-	if (!tr->ctrl || tracing_disabled)
+	if (tracing_disabled)
 		return 0;
 
 	pc = preempt_count();
@@ -3365,7 +3356,6 @@ __init static int tracer_alloc_buffers(void)
 #endif
 
 	/* All seems OK, enable tracing */
-	global_trace.ctrl = 1;
 	tracing_disabled = 0;
 
 	atomic_notifier_chain_register(&panic_notifier_list,
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index e481edaae1c4..cfda9d219e66 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -172,7 +172,6 @@ struct trace_iterator;
 struct trace_array {
 	struct ring_buffer	*buffer;
 	unsigned long		entries;
-	long			ctrl;
 	int			cpu;
 	cycle_t			time_start;
 	struct task_struct	*waiter;
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index e980b872bef5..8693b7a0a5b2 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -44,14 +44,12 @@ static void stop_function_trace(struct trace_array *tr)
 
 static void function_trace_init(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		start_function_trace(tr);
+	start_function_trace(tr);
 }
 
 static void function_trace_reset(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		stop_function_trace(tr);
+	stop_function_trace(tr);
 }
 
 static void function_trace_start(struct trace_array *tr)
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index ffdf592a54e3..d919d4eaa7cc 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -383,15 +383,12 @@ static void __irqsoff_tracer_init(struct trace_array *tr)
 	irqsoff_trace = tr;
 	/* make sure that the tracer is visible */
 	smp_wmb();
-
-	if (tr->ctrl)
-		start_irqsoff_tracer(tr);
+	start_irqsoff_tracer(tr);
 }
 
 static void irqsoff_tracer_reset(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		stop_irqsoff_tracer(tr);
+	stop_irqsoff_tracer(tr);
 }
 
 static void irqsoff_tracer_start(struct trace_array *tr)
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index fa9354e78b57..51bcf370215e 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -34,17 +34,16 @@ static void mmio_trace_init(struct trace_array *tr)
 {
 	pr_debug("in %s\n", __func__);
 	mmio_trace_array = tr;
-	if (tr->ctrl) {
-		mmio_reset_data(tr);
-		enable_mmiotrace();
-	}
+
+	mmio_reset_data(tr);
+	enable_mmiotrace();
 }
 
 static void mmio_trace_reset(struct trace_array *tr)
 {
 	pr_debug("in %s\n", __func__);
-	if (tr->ctrl)
-		disable_mmiotrace();
+
+	disable_mmiotrace();
 	mmio_reset_data(tr);
 	mmio_trace_array = NULL;
 }
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index e3c5fbfcdd36..2ef1d227e7d8 100644
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -32,14 +32,12 @@ static void nop_trace_init(struct trace_array *tr)
 	for_each_online_cpu(cpu)
 		tracing_reset(tr, cpu);
 
-	if (tr->ctrl)
-		start_nop_trace(tr);
+	start_nop_trace(tr);
 }
 
 static void nop_trace_reset(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		stop_nop_trace(tr);
+	stop_nop_trace(tr);
 }
 
 struct tracer nop_trace __read_mostly =
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 7b73fd11e4aa..be35bdfe2e38 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -209,14 +209,12 @@ static void stop_sched_trace(struct trace_array *tr)
 static void sched_switch_trace_init(struct trace_array *tr)
 {
 	ctx_trace = tr;
-
-	if (tr->ctrl)
-		start_sched_trace(tr);
+	start_sched_trace(tr);
 }
 
 static void sched_switch_trace_reset(struct trace_array *tr)
 {
-	if (tr->ctrl && sched_ref)
+	if (sched_ref)
 		stop_sched_trace(tr);
 }
 
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 23e54d4e4d92..983f2b1478c9 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -334,18 +334,14 @@ static void stop_wakeup_tracer(struct trace_array *tr)
 static void wakeup_tracer_init(struct trace_array *tr)
 {
 	wakeup_trace = tr;
-
-	if (tr->ctrl)
-		start_wakeup_tracer(tr);
+	start_wakeup_tracer(tr);
 }
 
 static void wakeup_tracer_reset(struct trace_array *tr)
 {
-	if (tr->ctrl) {
-		stop_wakeup_tracer(tr);
-		/* make sure we put back any tasks we are tracing */
-		wakeup_reset(tr);
-	}
+	stop_wakeup_tracer(tr);
+	/* make sure we put back any tasks we are tracing */
+	wakeup_reset(tr);
 }
 
 static void wakeup_tracer_start(struct trace_array *tr)
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 746934340474..ea4e5d3b15df 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -110,7 +110,6 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 	ftrace_set_filter(func_name, strlen(func_name), 1);
 
 	/* enable tracing */
-	tr->ctrl = 1;
 	trace->init(tr);
 
 	/* Sleep for a 1/10 of a second */
@@ -181,7 +180,6 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
 	ftrace_enabled = 1;
 	tracer_enabled = 1;
 
-	tr->ctrl = 1;
 	trace->init(tr);
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
@@ -224,7 +222,6 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
 	int ret;
 
 	/* start the tracing */
-	tr->ctrl = 1;
 	trace->init(tr);
 	/* reset the max latency */
 	tracing_max_latency = 0;
@@ -261,7 +258,6 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
 	int ret;
 
 	/* start the tracing */
-	tr->ctrl = 1;
 	trace->init(tr);
 	/* reset the max latency */
 	tracing_max_latency = 0;
@@ -298,7 +294,6 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	int ret;
 
 	/* start the tracing */
-	tr->ctrl = 1;
 	trace->init(tr);
 
 	/* reset the max latency */
@@ -427,7 +422,6 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 	wait_for_completion(&isrt);
 
 	/* start the tracing */
-	tr->ctrl = 1;
 	trace->init(tr);
 	/* reset the max latency */
 	tracing_max_latency = 0;
@@ -484,7 +478,6 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr
 	int ret;
 
 	/* start the tracing */
-	tr->ctrl = 1;
 	trace->init(tr);
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
@@ -512,7 +505,6 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
 	int ret;
 
 	/* start the tracing */
-	tr->ctrl = 1;
 	trace->init(tr);
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index 8097430edff9..05f753422aea 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -265,14 +265,12 @@ static void stack_trace_init(struct trace_array *tr)
 {
 	sysprof_trace = tr;
 
-	if (tr->ctrl)
-		start_stack_trace(tr);
+	start_stack_trace(tr);
 }
 
 static void stack_trace_reset(struct trace_array *tr)
 {
-	if (tr->ctrl)
-		stop_stack_trace(tr);
+	stop_stack_trace(tr);
 }
 
 static struct tracer stack_trace __read_mostly =
-- 
cgit v1.2.3-59-g8ed1b


From 1c80025a49855b12fa09bb6db71820e3367b1369 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Sun, 16 Nov 2008 05:57:26 +0100
Subject: tracing/ftrace: change the type of the init() callback

Impact: extend the ->init() method with the ability to fail

This bring a way to know if the initialization of a tracer successed.
A tracer must return 0 on success and a traditional error (ie:
-ENOMEM) if it fails.

If a tracer fails to init, it is free to print a detailed warn. The
tracing api will not and switch to a new tracer will just return the
error from the init callback.

Note: this will be used for the return tracer.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace.c                  |  7 ++--
 kernel/trace/trace.h                  |  3 +-
 kernel/trace/trace_boot.c             |  3 +-
 kernel/trace/trace_branch.c           |  3 +-
 kernel/trace/trace_functions.c        |  3 +-
 kernel/trace/trace_functions_return.c |  3 +-
 kernel/trace/trace_irqsoff.c          |  9 +++--
 kernel/trace/trace_mmiotrace.c        |  3 +-
 kernel/trace/trace_nop.c              |  3 +-
 kernel/trace/trace_sched_switch.c     |  3 +-
 kernel/trace/trace_sched_wakeup.c     |  3 +-
 kernel/trace/trace_selftest.c         | 66 ++++++++++++++++++++++++++++++-----
 kernel/trace/trace_sysprof.c          |  3 +-
 13 files changed, 88 insertions(+), 24 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 80898f4870cc..396fda034e3f 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2638,8 +2638,11 @@ static int tracing_set_tracer(char *buf)
 		current_trace->reset(tr);
 
 	current_trace = t;
-	if (t->init)
-		t->init(tr);
+	if (t->init) {
+		ret = t->init(tr);
+		if (ret)
+			goto out;
+	}
 
 	trace_branch_enable(tr);
  out:
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 790ea8c0e1f3..cdbd5cc22be8 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -264,7 +264,8 @@ enum print_line_t {
  */
 struct tracer {
 	const char		*name;
-	void			(*init)(struct trace_array *tr);
+	/* Your tracer should raise a warning if init fails */
+	int			(*init)(struct trace_array *tr);
 	void			(*reset)(struct trace_array *tr);
 	void			(*start)(struct trace_array *tr);
 	void			(*stop)(struct trace_array *tr);
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index cb333b7fd113..a4fa2c57e34e 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -47,7 +47,7 @@ static void reset_boot_trace(struct trace_array *tr)
 		tracing_reset(tr, cpu);
 }
 
-static void boot_trace_init(struct trace_array *tr)
+static int boot_trace_init(struct trace_array *tr)
 {
 	int cpu;
 	boot_trace = tr;
@@ -56,6 +56,7 @@ static void boot_trace_init(struct trace_array *tr)
 		tracing_reset(tr, cpu);
 
 	tracing_sched_switch_assign_trace(tr);
+	return 0;
 }
 
 static enum print_line_t
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 85265553918f..44bd39539d61 100644
--- a/kernel/trace/trace_branch.c
+++ b/kernel/trace/trace_branch.c
@@ -125,7 +125,7 @@ static void stop_branch_trace(struct trace_array *tr)
 	disable_branch_tracing();
 }
 
-static void branch_trace_init(struct trace_array *tr)
+static int branch_trace_init(struct trace_array *tr)
 {
 	int cpu;
 
@@ -133,6 +133,7 @@ static void branch_trace_init(struct trace_array *tr)
 		tracing_reset(tr, cpu);
 
 	start_branch_trace(tr);
+	return 0;
 }
 
 static void branch_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 8693b7a0a5b2..e74f6d0a3216 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -42,9 +42,10 @@ static void stop_function_trace(struct trace_array *tr)
 	tracing_stop_cmdline_record();
 }
 
-static void function_trace_init(struct trace_array *tr)
+static int function_trace_init(struct trace_array *tr)
 {
 	start_function_trace(tr);
+	return 0;
 }
 
 static void function_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_functions_return.c b/kernel/trace/trace_functions_return.c
index 7680b21537dd..61185f756a13 100644
--- a/kernel/trace/trace_functions_return.c
+++ b/kernel/trace/trace_functions_return.c
@@ -24,13 +24,14 @@ static void stop_return_trace(struct trace_array *tr)
 	unregister_ftrace_return();
 }
 
-static void return_trace_init(struct trace_array *tr)
+static int return_trace_init(struct trace_array *tr)
 {
 	int cpu;
 	for_each_online_cpu(cpu)
 		tracing_reset(tr, cpu);
 
 	start_return_trace(tr);
+	return 0;
 }
 
 static void return_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
index d919d4eaa7cc..7c2e326bbc8b 100644
--- a/kernel/trace/trace_irqsoff.c
+++ b/kernel/trace/trace_irqsoff.c
@@ -416,11 +416,12 @@ static void irqsoff_tracer_close(struct trace_iterator *iter)
 }
 
 #ifdef CONFIG_IRQSOFF_TRACER
-static void irqsoff_tracer_init(struct trace_array *tr)
+static int irqsoff_tracer_init(struct trace_array *tr)
 {
 	trace_type = TRACER_IRQS_OFF;
 
 	__irqsoff_tracer_init(tr);
+	return 0;
 }
 static struct tracer irqsoff_tracer __read_mostly =
 {
@@ -442,11 +443,12 @@ static struct tracer irqsoff_tracer __read_mostly =
 #endif
 
 #ifdef CONFIG_PREEMPT_TRACER
-static void preemptoff_tracer_init(struct trace_array *tr)
+static int preemptoff_tracer_init(struct trace_array *tr)
 {
 	trace_type = TRACER_PREEMPT_OFF;
 
 	__irqsoff_tracer_init(tr);
+	return 0;
 }
 
 static struct tracer preemptoff_tracer __read_mostly =
@@ -471,11 +473,12 @@ static struct tracer preemptoff_tracer __read_mostly =
 #if defined(CONFIG_IRQSOFF_TRACER) && \
 	defined(CONFIG_PREEMPT_TRACER)
 
-static void preemptirqsoff_tracer_init(struct trace_array *tr)
+static int preemptirqsoff_tracer_init(struct trace_array *tr)
 {
 	trace_type = TRACER_IRQS_OFF | TRACER_PREEMPT_OFF;
 
 	__irqsoff_tracer_init(tr);
+	return 0;
 }
 
 static struct tracer preemptirqsoff_tracer __read_mostly =
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index 51bcf370215e..433d650eda9f 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -30,13 +30,14 @@ static void mmio_reset_data(struct trace_array *tr)
 		tracing_reset(tr, cpu);
 }
 
-static void mmio_trace_init(struct trace_array *tr)
+static int mmio_trace_init(struct trace_array *tr)
 {
 	pr_debug("in %s\n", __func__);
 	mmio_trace_array = tr;
 
 	mmio_reset_data(tr);
 	enable_mmiotrace();
+	return 0;
 }
 
 static void mmio_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c
index 2ef1d227e7d8..0e77415caed3 100644
--- a/kernel/trace/trace_nop.c
+++ b/kernel/trace/trace_nop.c
@@ -24,7 +24,7 @@ static void stop_nop_trace(struct trace_array *tr)
 	/* Nothing to do! */
 }
 
-static void nop_trace_init(struct trace_array *tr)
+static int nop_trace_init(struct trace_array *tr)
 {
 	int cpu;
 	ctx_trace = tr;
@@ -33,6 +33,7 @@ static void nop_trace_init(struct trace_array *tr)
 		tracing_reset(tr, cpu);
 
 	start_nop_trace(tr);
+	return 0;
 }
 
 static void nop_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index be35bdfe2e38..863390557b44 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -206,10 +206,11 @@ static void stop_sched_trace(struct trace_array *tr)
 	tracing_stop_sched_switch_record();
 }
 
-static void sched_switch_trace_init(struct trace_array *tr)
+static int sched_switch_trace_init(struct trace_array *tr)
 {
 	ctx_trace = tr;
 	start_sched_trace(tr);
+	return 0;
 }
 
 static void sched_switch_trace_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 983f2b1478c9..0067b49746c1 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -331,10 +331,11 @@ static void stop_wakeup_tracer(struct trace_array *tr)
 	unregister_trace_sched_wakeup(probe_wakeup);
 }
 
-static void wakeup_tracer_init(struct trace_array *tr)
+static int wakeup_tracer_init(struct trace_array *tr)
 {
 	wakeup_trace = tr;
 	start_wakeup_tracer(tr);
+	return 0;
 }
 
 static void wakeup_tracer_reset(struct trace_array *tr)
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index 5cb64ea061b5..88c8eb70f54a 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -71,6 +71,11 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count)
 	return ret;
 }
 
+static inline void warn_failed_init_tracer(struct tracer *trace, int init_ret)
+{
+	printk(KERN_WARNING "Failed to init %s tracer, init returned %d\n",
+		trace->name, init_ret);
+}
 #ifdef CONFIG_FUNCTION_TRACER
 
 #ifdef CONFIG_DYNAMIC_FTRACE
@@ -111,7 +116,11 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
 	ftrace_set_filter(func_name, strlen(func_name), 1);
 
 	/* enable tracing */
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		goto out;
+	}
 
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
@@ -181,7 +190,12 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
 	ftrace_enabled = 1;
 	tracer_enabled = 1;
 
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		goto out;
+	}
+
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
 	/* stop the tracing. */
@@ -223,7 +237,12 @@ trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr)
 	int ret;
 
 	/* start the tracing */
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return ret;
+	}
+
 	/* reset the max latency */
 	tracing_max_latency = 0;
 	/* disable interrupts for a bit */
@@ -272,7 +291,12 @@ trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr)
 	}
 
 	/* start the tracing */
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return ret;
+	}
+
 	/* reset the max latency */
 	tracing_max_latency = 0;
 	/* disable preemption for a bit */
@@ -321,7 +345,11 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *
 	}
 
 	/* start the tracing */
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		goto out;
+	}
 
 	/* reset the max latency */
 	tracing_max_latency = 0;
@@ -449,7 +477,12 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr)
 	wait_for_completion(&isrt);
 
 	/* start the tracing */
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return ret;
+	}
+
 	/* reset the max latency */
 	tracing_max_latency = 0;
 
@@ -505,7 +538,12 @@ trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr
 	int ret;
 
 	/* start the tracing */
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return ret;
+	}
+
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
 	/* stop the tracing. */
@@ -532,7 +570,12 @@ trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr)
 	int ret;
 
 	/* start the tracing */
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return 0;
+	}
+
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
 	/* stop the tracing. */
@@ -554,7 +597,12 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
 	int ret;
 
 	/* start the tracing */
-	trace->init(tr);
+	ret = trace->init(tr);
+	if (ret) {
+		warn_failed_init_tracer(trace, ret);
+		return ret;
+	}
+
 	/* Sleep for a 1/10 of a second */
 	msleep(100);
 	/* stop the tracing. */
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index 05f753422aea..54960edb96d0 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -261,11 +261,12 @@ static void stop_stack_trace(struct trace_array *tr)
 	mutex_unlock(&sample_timer_lock);
 }
 
-static void stack_trace_init(struct trace_array *tr)
+static int stack_trace_init(struct trace_array *tr)
 {
 	sysprof_trace = tr;
 
 	start_stack_trace(tr);
+	return 0;
 }
 
 static void stack_trace_reset(struct trace_array *tr)
-- 
cgit v1.2.3-59-g8ed1b


From c71dd42db2c6f1637b92502a214587431c1a6ad2 Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 19 Dec 2008 01:09:51 +0100
Subject: tracing: fix warnings in kernel/trace/trace_sched_switch.c
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

these warnings:

  kernel/trace/trace_sched_switch.c: In function ‘tracing_sched_register’:
  kernel/trace/trace_sched_switch.c:96: warning: passing argument 1 of ‘register_trace_sched_wakeup_new’ from incompatible pointer type
  kernel/trace/trace_sched_switch.c:112: warning: passing argument 1 of ‘unregister_trace_sched_wakeup_new’ from incompatible pointer type
  kernel/trace/trace_sched_switch.c: In function ‘tracing_sched_unregister’:
  kernel/trace/trace_sched_switch.c:121: warning: passing argument 1 of ‘unregister_trace_sched_wakeup_new’ from incompatible pointer type

Trigger because sched_wakeup_new tracepoints need the same trace
signature as sched_wakeup - which was changed recently.

Fix it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 include/trace/sched.h             | 4 ++--
 kernel/sched.c                    | 2 +-
 kernel/trace/trace_sched_switch.c | 1 +
 3 files changed, 4 insertions(+), 3 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/include/trace/sched.h b/include/trace/sched.h
index f4549d506b16..bc4c9eadc6ba 100644
--- a/include/trace/sched.h
+++ b/include/trace/sched.h
@@ -21,8 +21,8 @@ DECLARE_TRACE(sched_wakeup,
 		TPARGS(rq, p));
 
 DECLARE_TRACE(sched_wakeup_new,
-	TPPROTO(struct rq *rq, struct task_struct *p),
-		TPARGS(rq, p));
+	TPPROTO(struct rq *rq, struct task_struct *p, int success),
+		TPARGS(rq, p, success));
 
 DECLARE_TRACE(sched_switch,
 	TPPROTO(struct rq *rq, struct task_struct *prev,
diff --git a/kernel/sched.c b/kernel/sched.c
index d377097572f9..ac5a70a87d1e 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2457,7 +2457,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
 		p->sched_class->task_new(rq, p);
 		inc_nr_running(rq);
 	}
-	trace_sched_wakeup_new(rq, p);
+	trace_sched_wakeup_new(rq, p, 1);
 	check_preempt_curr(rq, p, 0);
 #ifdef CONFIG_SMP
 	if (p->sched_class->task_wake_up)
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 863390557b44..781d72ef873c 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -247,3 +247,4 @@ __init static int init_sched_switch_trace(void)
 	return register_tracer(&sched_switch_trace);
 }
 device_initcall(init_sched_switch_trace);
+
-- 
cgit v1.2.3-59-g8ed1b


From 213cc060797378059a28ebc5c539f3e9a80160bd Mon Sep 17 00:00:00 2001
From: Pekka J Enberg <penberg@cs.helsinki.fi>
Date: Fri, 19 Dec 2008 12:08:39 +0200
Subject: ftrace: introduce tracing_reset_online_cpus() helper

Impact: cleanup

This patch factors out common code from multiple tracers into a
tracing_reset_online_cpus() function and converts the tracers to use it.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 kernel/trace/trace.c              | 10 ++++++++++
 kernel/trace/trace.h              |  1 +
 kernel/trace/trace_boot.c         | 12 +-----------
 kernel/trace/trace_functions.c    | 14 ++------------
 kernel/trace/trace_hw_branches.c  | 14 ++------------
 kernel/trace/trace_mmiotrace.c    |  6 +-----
 kernel/trace/trace_sched_switch.c | 14 ++------------
 kernel/trace/trace_sysprof.c      | 12 +-----------
 8 files changed, 20 insertions(+), 63 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 0eb6d48347f7..79db26e8216e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -679,6 +679,16 @@ void tracing_reset(struct trace_array *tr, int cpu)
 	ftrace_enable_cpu();
 }
 
+void tracing_reset_online_cpus(struct trace_array *tr)
+{
+	int cpu;
+
+	tr->time_start = ftrace_now(tr->cpu);
+
+	for_each_online_cpu(cpu)
+		tracing_reset(tr, cpu);
+}
+
 #define SAVED_CMDLINES 128
 static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
 static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index fc75dce7a664..cc7a4f864036 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -374,6 +374,7 @@ struct trace_iterator {
 int tracing_is_enabled(void);
 void trace_wake_up(void);
 void tracing_reset(struct trace_array *tr, int cpu);
+void tracing_reset_online_cpus(struct trace_array *tr);
 int tracing_open_generic(struct inode *inode, struct file *filp);
 struct dentry *tracing_init_dentry(void);
 void init_tracer_sysprof_debugfs(struct dentry *d_tracer);
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index a4fa2c57e34e..3ccebde28482 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -37,16 +37,6 @@ void disable_boot_trace(void)
 		tracing_stop_sched_switch_record();
 }
 
-static void reset_boot_trace(struct trace_array *tr)
-{
-	int cpu;
-
-	tr->time_start = ftrace_now(tr->cpu);
-
-	for_each_online_cpu(cpu)
-		tracing_reset(tr, cpu);
-}
-
 static int boot_trace_init(struct trace_array *tr)
 {
 	int cpu;
@@ -130,7 +120,7 @@ struct tracer boot_tracer __read_mostly =
 {
 	.name		= "initcall",
 	.init		= boot_trace_init,
-	.reset		= reset_boot_trace,
+	.reset		= tracing_reset_online_cpus,
 	.print_line	= initcall_print_line,
 };
 
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index e74f6d0a3216..9236d7e25a16 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -16,20 +16,10 @@
 
 #include "trace.h"
 
-static void function_reset(struct trace_array *tr)
-{
-	int cpu;
-
-	tr->time_start = ftrace_now(tr->cpu);
-
-	for_each_online_cpu(cpu)
-		tracing_reset(tr, cpu);
-}
-
 static void start_function_trace(struct trace_array *tr)
 {
 	tr->cpu = get_cpu();
-	function_reset(tr);
+	tracing_reset_online_cpus(tr);
 	put_cpu();
 
 	tracing_start_cmdline_record();
@@ -55,7 +45,7 @@ static void function_trace_reset(struct trace_array *tr)
 
 static void function_trace_start(struct trace_array *tr)
 {
-	function_reset(tr);
+	tracing_reset_online_cpus(tr);
 }
 
 static struct tracer function_trace __read_mostly =
diff --git a/kernel/trace/trace_hw_branches.c b/kernel/trace/trace_hw_branches.c
index ee29e012aa97..b6a3e20a49a9 100644
--- a/kernel/trace/trace_hw_branches.c
+++ b/kernel/trace/trace_hw_branches.c
@@ -25,16 +25,6 @@ static DEFINE_PER_CPU(unsigned char[SIZEOF_BTS], buffer);
 #define this_buffer per_cpu(buffer, smp_processor_id())
 
 
-static void bts_trace_reset(struct trace_array *tr)
-{
-	int cpu;
-
-	tr->time_start = ftrace_now(tr->cpu);
-
-	for_each_online_cpu(cpu)
-		tracing_reset(tr, cpu);
-}
-
 static void bts_trace_start_cpu(void *arg)
 {
 	if (this_tracer)
@@ -54,7 +44,7 @@ static void bts_trace_start(struct trace_array *tr)
 {
 	int cpu;
 
-	bts_trace_reset(tr);
+	tracing_reset_online_cpus(tr);
 
 	for_each_cpu_mask(cpu, cpu_possible_map)
 		smp_call_function_single(cpu, bts_trace_start_cpu, NULL, 1);
@@ -78,7 +68,7 @@ static void bts_trace_stop(struct trace_array *tr)
 
 static int bts_trace_init(struct trace_array *tr)
 {
-	bts_trace_reset(tr);
+	tracing_reset_online_cpus(tr);
 	bts_trace_start(tr);
 
 	return 0;
diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index 2fb6da6523b3..fffcb069f1dc 100644
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -22,14 +22,10 @@ static unsigned long prev_overruns;
 
 static void mmio_reset_data(struct trace_array *tr)
 {
-	int cpu;
-
 	overrun_detected = false;
 	prev_overruns = 0;
-	tr->time_start = ftrace_now(tr->cpu);
 
-	for_each_online_cpu(cpu)
-		tracing_reset(tr, cpu);
+	tracing_reset_online_cpus(tr);
 }
 
 static int mmio_trace_init(struct trace_array *tr)
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 781d72ef873c..add2c1fdae92 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -72,16 +72,6 @@ probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee)
 	local_irq_restore(flags);
 }
 
-static void sched_switch_reset(struct trace_array *tr)
-{
-	int cpu;
-
-	tr->time_start = ftrace_now(tr->cpu);
-
-	for_each_online_cpu(cpu)
-		tracing_reset(tr, cpu);
-}
-
 static int tracing_sched_register(void)
 {
 	int ret;
@@ -197,7 +187,7 @@ void tracing_sched_switch_assign_trace(struct trace_array *tr)
 
 static void start_sched_trace(struct trace_array *tr)
 {
-	sched_switch_reset(tr);
+	tracing_reset_online_cpus(tr);
 	tracing_start_sched_switch_record();
 }
 
@@ -221,7 +211,7 @@ static void sched_switch_trace_reset(struct trace_array *tr)
 
 static void sched_switch_trace_start(struct trace_array *tr)
 {
-	sched_switch_reset(tr);
+	tracing_reset_online_cpus(tr);
 	tracing_start_sched_switch();
 }
 
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index 54960edb96d0..01becf1f19ff 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -234,20 +234,10 @@ static void stop_stack_timers(void)
 		stop_stack_timer(cpu);
 }
 
-static void stack_reset(struct trace_array *tr)
-{
-	int cpu;
-
-	tr->time_start = ftrace_now(tr->cpu);
-
-	for_each_online_cpu(cpu)
-		tracing_reset(tr, cpu);
-}
-
 static void start_stack_trace(struct trace_array *tr)
 {
 	mutex_lock(&sample_timer_lock);
-	stack_reset(tr);
+	tracing_reset_online_cpus(tr);
 	start_stack_timers();
 	tracer_enabled = 1;
 	mutex_unlock(&sample_timer_lock);
-- 
cgit v1.2.3-59-g8ed1b


From 468a15bb4cc61694495cc5ed7ffca29e87c79b69 Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Tue, 16 Dec 2008 08:07:03 +0100
Subject: sched, trace: update trace_sched_wakeup()

Impact: extend the wakeup tracepoint with the info whether the wakeup was real

Add the information needed to distinguish 'real' wakeups from 'false'
wakeups.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 include/trace/sched.h             | 4 ++--
 kernel/sched.c                    | 2 +-
 kernel/trace/trace_sched_switch.c | 2 +-
 kernel/trace/trace_sched_wakeup.c | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

(limited to 'kernel/trace/trace_sched_switch.c')

diff --git a/include/trace/sched.h b/include/trace/sched.h
index bc4c9eadc6ba..0d81098ee9fc 100644
--- a/include/trace/sched.h
+++ b/include/trace/sched.h
@@ -17,8 +17,8 @@ DECLARE_TRACE(sched_wait_task,
 		TPARGS(rq, p));
 
 DECLARE_TRACE(sched_wakeup,
-	TPPROTO(struct rq *rq, struct task_struct *p),
-		TPARGS(rq, p));
+	TPPROTO(struct rq *rq, struct task_struct *p, int success),
+		TPARGS(rq, p, success));
 
 DECLARE_TRACE(sched_wakeup_new,
 	TPPROTO(struct rq *rq, struct task_struct *p, int success),
diff --git a/kernel/sched.c b/kernel/sched.c
index ceda5799466e..dcb39bc88f6c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2324,7 +2324,7 @@ out_activate:
 	success = 1;
 
 out_running:
-	trace_sched_wakeup(rq, p);
+	trace_sched_wakeup(rq, p, success);
 	check_preempt_curr(rq, p, sync);
 
 	p->state = TASK_RUNNING;
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index add2c1fdae92..df175cb4564f 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -49,7 +49,7 @@ probe_sched_switch(struct rq *__rq, struct task_struct *prev,
 }
 
 static void
-probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee)
+probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee, int success)
 {
 	struct trace_array_cpu *data;
 	unsigned long flags;
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index 0067b49746c1..43586b689e31 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -211,7 +211,7 @@ static void wakeup_reset(struct trace_array *tr)
 }
 
 static void
-probe_wakeup(struct rq *rq, struct task_struct *p)
+probe_wakeup(struct rq *rq, struct task_struct *p, int success)
 {
 	int cpu = smp_processor_id();
 	unsigned long flags;
-- 
cgit v1.2.3-59-g8ed1b