[PATCH 0/2] [GIT PULL][v3.7] tracing: A couple more updates

[PATCH 0/2] [GIT PULL][v3.7] tracing: A couple more updates

[Steven Rostedt]

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Ingo,

Please pull the latest tip/perf/core tree, which can be found at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
tip/perf/core

Head SHA1: 8781915ad2716adcd8cd5cc52cee791fc8b00fdf


Ezequiel Garcia (1):
      trace: Move trace event enable from fs_initcall to core_initcall

Mandeep Singh Baines (1):
      tracing: Add an option for disabling markers

----
 kernel/trace/trace.c          |    6 ++-
 kernel/trace/trace.h          |    1 +
 kernel/trace/trace_events.c   |  108 +++++++++++++++++++++++++++--------------
 kernel/trace/trace_syscalls.c |    2 +-
 4 files changed, 79 insertions(+), 38 deletions(-)

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[PATCH 1/2] tracing: Add an option for disabling markers

[Steven Rostedt]

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From: Mandeep Singh Baines <mandeep.baines@gmail.com>

In our application, we have trace markers spread through user-space.
We have markers in GL, X, etc. These are super handy for Chrome's
about:tracing feature (Chrome + system + kernel trace view), but
can be very distracting when you're trying to debug a kernel issue.

I normally, use "grep -v tracing_mark_write" but it would be nice
if I could just temporarily disable markers all together.

Link: http://lkml.kernel.org/r/1347066739-26285-1-git-send-email-msb@chromium.org

CC: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace.c |    6 +++++-
 kernel/trace/trace.h |    1 +
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 08acf42..1ec5c1d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -328,7 +328,7 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait);
 unsigned long trace_flags = TRACE_ITER_PRINT_PARENT | TRACE_ITER_PRINTK |
 	TRACE_ITER_ANNOTATE | TRACE_ITER_CONTEXT_INFO | TRACE_ITER_SLEEP_TIME |
 	TRACE_ITER_GRAPH_TIME | TRACE_ITER_RECORD_CMD | TRACE_ITER_OVERWRITE |
-	TRACE_ITER_IRQ_INFO;
+	TRACE_ITER_IRQ_INFO | TRACE_ITER_MARKERS;
 
 static int trace_stop_count;
 static DEFINE_RAW_SPINLOCK(tracing_start_lock);
@@ -470,6 +470,7 @@ static const char *trace_options[] = {
 	"overwrite",
 	"disable_on_free",
 	"irq-info",
+	"markers",
 	NULL
 };
 
@@ -3886,6 +3887,9 @@ tracing_mark_write(struct file *filp, const char __user *ubuf,
 	if (tracing_disabled)
 		return -EINVAL;
 
+	if (!(trace_flags & TRACE_ITER_MARKERS))
+		return -EINVAL;
+
 	if (cnt > TRACE_BUF_SIZE)
 		cnt = TRACE_BUF_SIZE;
 
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 593debe..63a2da0 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -680,6 +680,7 @@ enum trace_iterator_flags {
 	TRACE_ITER_OVERWRITE		= 0x200000,
 	TRACE_ITER_STOP_ON_FREE		= 0x400000,
 	TRACE_ITER_IRQ_INFO		= 0x800000,
+	TRACE_ITER_MARKERS		= 0x1000000,
 };
 
 /*
-- 
1.7.10.4



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[PATCH 2/2] trace: Move trace event enable from fs_initcall to core_initcall

[Steven Rostedt]

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From: Ezequiel Garcia <elezegarcia@gmail.com>

This patch splits trace event initialization in two stages:
 * ftrace enable
 * sysfs event entry creation

This allows to capture trace events from an earlier point
by using 'trace_event' kernel parameter and is important
to trace boot-up allocations.

Note that, in order to enable events at core_initcall,
it's necessary to move init_ftrace_syscalls() from
core_initcall to early_initcall.

Link: http://lkml.kernel.org/r/1347461277-25302-1-git-send-email-elezegarcia@gmail.com

Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/trace/trace_events.c   |  108 +++++++++++++++++++++++++++--------------
 kernel/trace/trace_syscalls.c |    2 +-
 2 files changed, 73 insertions(+), 37 deletions(-)

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index bbb0e63..d608d09 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1199,6 +1199,31 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
 	return 0;
 }
 
+static void event_remove(struct ftrace_event_call *call)
+{
+	ftrace_event_enable_disable(call, 0);
+	if (call->event.funcs)
+		__unregister_ftrace_event(&call->event);
+	list_del(&call->list);
+}
+
+static int event_init(struct ftrace_event_call *call)
+{
+	int ret = 0;
+
+	if (WARN_ON(!call->name))
+		return -EINVAL;
+
+	if (call->class->raw_init) {
+		ret = call->class->raw_init(call);
+		if (ret < 0 && ret != -ENOSYS)
+			pr_warn("Could not initialize trace events/%s\n",
+				call->name);
+	}
+
+	return ret;
+}
+
 static int
 __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
 		       const struct file_operations *id,
@@ -1209,19 +1234,9 @@ __trace_add_event_call(struct ftrace_event_call *call, struct module *mod,
 	struct dentry *d_events;
 	int ret;
 
-	/* The linker may leave blanks */
-	if (!call->name)
-		return -EINVAL;
-
-	if (call->class->raw_init) {
-		ret = call->class->raw_init(call);
-		if (ret < 0) {
-			if (ret != -ENOSYS)
-				pr_warning("Could not initialize trace events/%s\n",
-					   call->name);
-			return ret;
-		}
-	}
+	ret = event_init(call);
+	if (ret < 0)
+		return ret;
 
 	d_events = event_trace_events_dir();
 	if (!d_events)
@@ -1272,13 +1287,10 @@ static void remove_subsystem_dir(const char *name)
  */
 static void __trace_remove_event_call(struct ftrace_event_call *call)
 {
-	ftrace_event_enable_disable(call, 0);
-	if (call->event.funcs)
-		__unregister_ftrace_event(&call->event);
-	debugfs_remove_recursive(call->dir);
-	list_del(&call->list);
+	event_remove(call);
 	trace_destroy_fields(call);
 	destroy_preds(call);
+	debugfs_remove_recursive(call->dir);
 	remove_subsystem_dir(call->class->system);
 }
 
@@ -1450,15 +1462,43 @@ static __init int setup_trace_event(char *str)
 }
 __setup("trace_event=", setup_trace_event);
 
+static __init int event_trace_enable(void)
+{
+	struct ftrace_event_call **iter, *call;
+	char *buf = bootup_event_buf;
+	char *token;
+	int ret;
+
+	for_each_event(iter, __start_ftrace_events, __stop_ftrace_events) {
+
+		call = *iter;
+		ret = event_init(call);
+		if (!ret)
+			list_add(&call->list, &ftrace_events);
+	}
+
+	while (true) {
+		token = strsep(&buf, ",");
+
+		if (!token)
+			break;
+		if (!*token)
+			continue;
+
+		ret = ftrace_set_clr_event(token, 1);
+		if (ret)
+			pr_warn("Failed to enable trace event: %s\n", token);
+	}
+	return 0;
+}
+
 static __init int event_trace_init(void)
 {
-	struct ftrace_event_call **call;
+	struct ftrace_event_call *call;
 	struct dentry *d_tracer;
 	struct dentry *entry;
 	struct dentry *d_events;
 	int ret;
-	char *buf = bootup_event_buf;
-	char *token;
 
 	d_tracer = tracing_init_dentry();
 	if (!d_tracer)
@@ -1497,24 +1537,19 @@ static __init int event_trace_init(void)
 	if (trace_define_common_fields())
 		pr_warning("tracing: Failed to allocate common fields");
 
-	for_each_event(call, __start_ftrace_events, __stop_ftrace_events) {
-		__trace_add_event_call(*call, NULL, &ftrace_event_id_fops,
+	/*
+	 * Early initialization already enabled ftrace event.
+	 * Now it's only necessary to create the event directory.
+	 */
+	list_for_each_entry(call, &ftrace_events, list) {
+
+		ret = event_create_dir(call, d_events,
+				       &ftrace_event_id_fops,
 				       &ftrace_enable_fops,
 				       &ftrace_event_filter_fops,
 				       &ftrace_event_format_fops);
-	}
-
-	while (true) {
-		token = strsep(&buf, ",");
-
-		if (!token)
-			break;
-		if (!*token)
-			continue;
-
-		ret = ftrace_set_clr_event(token, 1);
-		if (ret)
-			pr_warning("Failed to enable trace event: %s\n", token);
+		if (ret < 0)
+			event_remove(call);
 	}
 
 	ret = register_module_notifier(&trace_module_nb);
@@ -1523,6 +1558,7 @@ static __init int event_trace_init(void)
 
 	return 0;
 }
+core_initcall(event_trace_enable);
 fs_initcall(event_trace_init);
 
 #ifdef CONFIG_FTRACE_STARTUP_TEST
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 6b245f64..2485a7d 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -487,7 +487,7 @@ int __init init_ftrace_syscalls(void)
 
 	return 0;
 }
-core_initcall(init_ftrace_syscalls);
+early_initcall(init_ftrace_syscalls);
 
 #ifdef CONFIG_PERF_EVENTS
 
-- 
1.7.10.4



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Re: [PATCH 0/2] [GIT PULL][v3.7] tracing: A couple more updates

[Ingo Molnar]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> 
> Ingo,
> 
> Please pull the latest tip/perf/core tree, which can be found at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
> tip/perf/core
> 
> Head SHA1: 8781915ad2716adcd8cd5cc52cee791fc8b00fdf
> 
> 
> Ezequiel Garcia (1):
>       trace: Move trace event enable from fs_initcall to core_initcall
> 
> Mandeep Singh Baines (1):
>       tracing: Add an option for disabling markers
> 
> ----
>  kernel/trace/trace.c          |    6 ++-
>  kernel/trace/trace.h          |    1 +
>  kernel/trace/trace_events.c   |  108 +++++++++++++++++++++++++++--------------
>  kernel/trace/trace_syscalls.c |    2 +-
>  4 files changed, 79 insertions(+), 38 deletions(-)

Pulled, thanks Steve!

	Ingo