[v2,3/3] trace-cmd: Making stat to report when the stack tracer is ON
diff mbox series

Message ID 20171221152520.25867-4-vladislav.valtchev@gmail.com
State New, archived
Headers show
Series
  • trace-cmd: Integrate stack tracer status in 'stat'
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Commit Message

Vladislav Valtchev (VMware) Dec. 21, 2017, 3:25 p.m. UTC
trace-cmd stat is a handy way for users to see what tracing is currently going
on, but currently it does not say anything about the stack tracing. This patch
makes the command to show a message when the stack tracer is ON.

Signed-off-by: Vladislav Valtchev (VMware) <vladislav.valtchev@gmail.com>
---
 trace-cmd.h   | 2 ++
 trace-stack.c | 6 ++++++
 trace-stat.c  | 8 ++++++++
 3 files changed, 16 insertions(+)

Comments

Steven Rostedt Jan. 12, 2018, 3:47 p.m. UTC | #1
On Thu, 21 Dec 2017 17:25:20 +0200
"Vladislav Valtchev (VMware)" <vladislav.valtchev@gmail.com> wrote:

> trace-cmd stat is a handy way for users to see what tracing is currently going
> on, but currently it does not say anything about the stack tracing. This patch
> makes the command to show a message when the stack tracer is ON.
> 
> Signed-off-by: Vladislav Valtchev (VMware) <vladislav.valtchev@gmail.com>
> ---
>  trace-cmd.h   | 2 ++
>  trace-stack.c | 6 ++++++
>  trace-stat.c  | 8 ++++++++
>  3 files changed, 16 insertions(+)
> 
> diff --git a/trace-cmd.h b/trace-cmd.h
> index 6fd34d7..9704b2e 100644
> --- a/trace-cmd.h
> +++ b/trace-cmd.h
> @@ -358,6 +358,8 @@ void tracecmd_free_hooks(struct hook_list *hooks);
>  /* --- Hack! --- */
>  int tracecmd_blk_hack(struct tracecmd_input *handle);
>  
> +/* --- Stack tracer functions --- */
> +int tracecmd_stack_tracer_status(int *status);
>  
>  /* --- Debugging --- */
>  struct kbuffer *tracecmd_record_kbuf(struct tracecmd_input *handle,
> diff --git a/trace-stack.c b/trace-stack.c
> index d55d994..0028ecc 100644
> --- a/trace-stack.c
> +++ b/trace-stack.c
> @@ -107,6 +107,12 @@ static int read_proc(int *status)
>  	return 1; /* full success */
>  }
>  
> +/* Public wrapper of read_proc() */
> +int tracecmd_stack_tracer_status(int *status)
> +{
> +	return read_proc(status);
> +}
> +
>  /* NOTE: this implementation only accepts new_status in the range [0..9]. */
>  static void change_stack_tracer_status(int new_status)
>  {
> diff --git a/trace-stat.c b/trace-stat.c
> index fd16354..61dd41f 100644
> --- a/trace-stat.c
> +++ b/trace-stat.c
> @@ -894,6 +894,7 @@ void trace_stat (int argc, char **argv)
>  	struct buffer_instance *instance = &top_instance;
>  	int topt = 0;
>  	int c;
> +	int stack_tracer_status;

Needs to be upside down x-mas tree. (can't you feel the season?) ;-)

Not to mention, it's an awfully verbose variable name. Just call it
"status".

>  
>  	for (;;) {
>  		c = getopt(argc-1, argv+1, "tB:");
> @@ -928,5 +929,12 @@ void trace_stat (int argc, char **argv)
>  		stat_instance(instance);
>  	}
>  
> +	if (tracecmd_stack_tracer_status(&stack_tracer_status) >= 0) {
> +		if (stack_tracer_status > 0)
> +			printf("Stack tracing is enabled\n\n");
> +	} else {
> +		printf("The status of the stack tracer is indeterminate\n\n");

I wonder if we should report saying there was an error?

	printf("Error reading stack tracer status\n");

-- Steve

> +	}
> +
>  	exit(0);
>  }

Patch
diff mbox series

diff --git a/trace-cmd.h b/trace-cmd.h
index 6fd34d7..9704b2e 100644
--- a/trace-cmd.h
+++ b/trace-cmd.h
@@ -358,6 +358,8 @@  void tracecmd_free_hooks(struct hook_list *hooks);
 /* --- Hack! --- */
 int tracecmd_blk_hack(struct tracecmd_input *handle);
 
+/* --- Stack tracer functions --- */
+int tracecmd_stack_tracer_status(int *status);
 
 /* --- Debugging --- */
 struct kbuffer *tracecmd_record_kbuf(struct tracecmd_input *handle,
diff --git a/trace-stack.c b/trace-stack.c
index d55d994..0028ecc 100644
--- a/trace-stack.c
+++ b/trace-stack.c
@@ -107,6 +107,12 @@  static int read_proc(int *status)
 	return 1; /* full success */
 }
 
+/* Public wrapper of read_proc() */
+int tracecmd_stack_tracer_status(int *status)
+{
+	return read_proc(status);
+}
+
 /* NOTE: this implementation only accepts new_status in the range [0..9]. */
 static void change_stack_tracer_status(int new_status)
 {
diff --git a/trace-stat.c b/trace-stat.c
index fd16354..61dd41f 100644
--- a/trace-stat.c
+++ b/trace-stat.c
@@ -894,6 +894,7 @@  void trace_stat (int argc, char **argv)
 	struct buffer_instance *instance = &top_instance;
 	int topt = 0;
 	int c;
+	int stack_tracer_status;
 
 	for (;;) {
 		c = getopt(argc-1, argv+1, "tB:");
@@ -928,5 +929,12 @@  void trace_stat (int argc, char **argv)
 		stat_instance(instance);
 	}
 
+	if (tracecmd_stack_tracer_status(&stack_tracer_status) >= 0) {
+		if (stack_tracer_status > 0)
+			printf("Stack tracing is enabled\n\n");
+	} else {
+		printf("The status of the stack tracer is indeterminate\n\n");
+	}
+
 	exit(0);
 }