[PATCH 1/2] kernel/trace: call helper function to check global_trace

[PATCH 1/2] kernel/trace: call helper function to check global_trace

[Yaowei Bai]

Use helper function tracing_is_enabled() to check if global_trace
has been disabled.

No functional change.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 6e79408..b0bd322a 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7111,7 +7111,7 @@ __init static int tracer_alloc_buffers(void)
 		goto out_free_savedcmd;
 	}
 
-	if (global_trace.buffer_disabled)
+	if (!tracing_is_enabled())
 		tracing_off();
 
 	if (trace_boot_clock) {
-- 
1.9.1

[PATCH 2/2] kernel/trace_probe: is_good_name can be boolean

[Yaowei Bai]

This patch makes is_good_name return bool to improve readability
due to this particular function only using either one or zero as its
return value.

No functional change.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
---
 kernel/trace/trace_probe.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index b98dee9..f6398db 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -302,15 +302,15 @@ static nokprobe_inline void call_fetch(struct fetch_param *fprm,
 }
 
 /* Check the name is good for event/group/fields */
-static inline int is_good_name(const char *name)
+static inline bool is_good_name(const char *name)
 {
 	if (!isalpha(*name) && *name != '_')
-		return 0;
+		return false;
 	while (*++name != '\0') {
 		if (!isalpha(*name) && !isdigit(*name) && *name != '_')
-			return 0;
+			return false;
 	}
-	return 1;
+	return true;
 }
 
 static inline struct event_file_link *
-- 
1.9.1

Re: [PATCH 1/2] kernel/trace: call helper function to check global_trace

[Steven Rostedt]

On Tue, 22 Sep 2015 21:43:12 +0800
Yaowei Bai <bywxiaobai@163.com> wrote:

> Use helper function tracing_is_enabled() to check if global_trace
> has been disabled.

Actually, I prefer not to.

> 
> No functional change.
> 
> Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
> ---
>  kernel/trace/trace.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 6e79408..b0bd322a 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -7111,7 +7111,7 @@ __init static int tracer_alloc_buffers(void)
>  		goto out_free_savedcmd;
>  	}
>  
> -	if (global_trace.buffer_disabled)
> +	if (!tracing_is_enabled())

Yes, the above is functionally equivalent. But tracing_is_enabled() is
not a "helper function" but actually an external interface for other
parts of the tracing system.

The above code is the actual setup of the tracing infrastructure, that
is used to allocate the tracing buffers. They may now use the same
logic, but there's no guarantee that it will in the future.

-- Steve


>  		tracing_off();
>  
>  	if (trace_boot_clock) {

Re: [PATCH 2/2] kernel/trace_probe: is_good_name can be boolean

[Steven Rostedt]

On Tue, 22 Sep 2015 21:43:13 +0800
Yaowei Bai <bywxiaobai@163.com> wrote:

> This patch makes is_good_name return bool to improve readability
> due to this particular function only using either one or zero as its
> return value.

This patch makes sense. I'll take it. Thanks!

-- Steve

> 
> No functional change.
> 
> Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
> ---
>  kernel/trace/trace_probe.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
> index b98dee9..f6398db 100644
> --- a/kernel/trace/trace_probe.h
> +++ b/kernel/trace/trace_probe.h
> @@ -302,15 +302,15 @@ static nokprobe_inline void call_fetch(struct fetch_param *fprm,
>  }
>  
>  /* Check the name is good for event/group/fields */
> -static inline int is_good_name(const char *name)
> +static inline bool is_good_name(const char *name)
>  {
>  	if (!isalpha(*name) && *name != '_')
> -		return 0;
> +		return false;
>  	while (*++name != '\0') {
>  		if (!isalpha(*name) && !isdigit(*name) && *name != '_')
> -			return 0;
> +			return false;
>  	}
> -	return 1;
> +	return true;
>  }
>  
>  static inline struct event_file_link *

Re: [PATCH 1/2] kernel/trace: call helper function to check global_trace

[Yaowei Bai]

On Tue, Sep 22, 2015 at 09:58:47AM -0400, Steven Rostedt wrote:
> On Tue, 22 Sep 2015 21:43:12 +0800
> Yaowei Bai <bywxiaobai@163.com> wrote:
> 
> > Use helper function tracing_is_enabled() to check if global_trace
> > has been disabled.
> 
> Actually, I prefer not to.
> 
> > 
> > No functional change.
> > 
> > Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
> > ---
> >  kernel/trace/trace.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> > index 6e79408..b0bd322a 100644
> > --- a/kernel/trace/trace.c
> > +++ b/kernel/trace/trace.c
> > @@ -7111,7 +7111,7 @@ __init static int tracer_alloc_buffers(void)
> >  		goto out_free_savedcmd;
> >  	}
> >  
> > -	if (global_trace.buffer_disabled)
> > +	if (!tracing_is_enabled())
> 
> Yes, the above is functionally equivalent. But tracing_is_enabled() is
> not a "helper function" but actually an external interface for other
> parts of the tracing system.

Got it.

> 
> The above code is the actual setup of the tracing infrastructure, that
> is used to allocate the tracing buffers. They may now use the same
> logic, but there's no guarantee that it will in the future.

Appreciate you wonderful explanation.

> 
> -- Steve
> 
> 
> >  		tracing_off();
> >  
> >  	if (trace_boot_clock) {