diff mbox series

tracing/eprobe: Iterate trace_eprobe directly

Message ID 20230810082523.244397-1-nashuiliang@gmail.com
State New
Headers
Series tracing/eprobe: Iterate trace_eprobe directly |

Commit Message

Chuang Wang Aug. 10, 2023, 8:25 a.m. UTC 
  Refer to the description in [1], we can skip "container_of()" following
"list_for_each_entry()" by using "list_for_each_entry()" with
"struct trace_eprobe" and "tp.list".

[1] https://lore.kernel.org/all/CAHk-=wjakjw6-rDzDDBsuMoDCqd+9ogifR_EE1F0K-jYek1CdA@mail.gmail.com/

Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
---
 kernel/trace/trace_eprobe.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

Comments

Masami Hiramatsu (Google) Aug. 10, 2023, 10:32 a.m. UTC | #1 
On Thu, 10 Aug 2023 16:25:23 +0800
Chuang Wang <nashuiliang@gmail.com> wrote:

> Refer to the description in [1], we can skip "container_of()" following
> "list_for_each_entry()" by using "list_for_each_entry()" with
> "struct trace_eprobe" and "tp.list".
> 
> [1] https://lore.kernel.org/all/CAHk-=wjakjw6-rDzDDBsuMoDCqd+9ogifR_EE1F0K-jYek1CdA@mail.gmail.com/
> 

Good point. BTW, it is better to have 'for_each_eprobe(ep)' if it repeats 3 times.


> Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")

This is not a bug, so no need Fixes tag.

Thank you,

> Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
> ---
>  kernel/trace/trace_eprobe.c | 13 +++++--------
>  1 file changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
> index a0a704ba27db..d68d660dff7c 100644
> --- a/kernel/trace/trace_eprobe.c
> +++ b/kernel/trace/trace_eprobe.c
> @@ -640,7 +640,7 @@ static int disable_eprobe(struct trace_eprobe *ep,
>  static int enable_trace_eprobe(struct trace_event_call *call,
>  			       struct trace_event_file *file)
>  {
> -	struct trace_probe *pos, *tp;
> +	struct trace_probe *tp;
>  	struct trace_eprobe *ep;
>  	bool enabled;
>  	int ret = 0;
> @@ -662,8 +662,7 @@ static int enable_trace_eprobe(struct trace_event_call *call,
>  	if (enabled)
>  		return 0;
>  
> -	list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
> -		ep = container_of(pos, struct trace_eprobe, tp);
> +	list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
>  		ret = enable_eprobe(ep, file);
>  		if (ret)
>  			break;
> @@ -680,8 +679,7 @@ static int enable_trace_eprobe(struct trace_event_call *call,
>  			 */
>  			WARN_ON_ONCE(ret != -ENOMEM);
>  
> -			list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
> -				ep = container_of(pos, struct trace_eprobe, tp);
> +			list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
>  				disable_eprobe(ep, file->tr);
>  				if (!--cnt)
>  					break;
> @@ -699,7 +697,7 @@ static int enable_trace_eprobe(struct trace_event_call *call,
>  static int disable_trace_eprobe(struct trace_event_call *call,
>  				struct trace_event_file *file)
>  {
> -	struct trace_probe *pos, *tp;
> +	struct trace_probe *tp;
>  	struct trace_eprobe *ep;
>  
>  	tp = trace_probe_primary_from_call(call);
> @@ -716,8 +714,7 @@ static int disable_trace_eprobe(struct trace_event_call *call,
>  		trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
>  
>  	if (!trace_probe_is_enabled(tp)) {
> -		list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
> -			ep = container_of(pos, struct trace_eprobe, tp);
> +		list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
>  			disable_eprobe(ep, file->tr);
>  		}
>  	}
> -- 
> 2.39.2
>
Masami Hiramatsu (Google) Aug. 11, 2023, 1:51 a.m. UTC | #2 
On Thu, 10 Aug 2023 19:32:04 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:

> On Thu, 10 Aug 2023 16:25:23 +0800
> Chuang Wang <nashuiliang@gmail.com> wrote:
> 
> > Refer to the description in [1], we can skip "container_of()" following
> > "list_for_each_entry()" by using "list_for_each_entry()" with
> > "struct trace_eprobe" and "tp.list".
> > 
> > [1] https://lore.kernel.org/all/CAHk-=wjakjw6-rDzDDBsuMoDCqd+9ogifR_EE1F0K-jYek1CdA@mail.gmail.com/
> > 
> 
> Good point. BTW, it is better to have 'for_each_eprobe(ep)' if it repeats 3 times.

Wait, it is for each trace_eprobe on the trace_probe.

#define for_each_trace_eprobe_on_trace_probe(ep, _tp)
	list_for_each_entry(ep, trace_probe_probe_list(_tp), tp.list)

Thank you,

> 
> 
> > Fixes: 7491e2c44278 ("tracing: Add a probe that attaches to trace events")
> 
> This is not a bug, so no need Fixes tag.
> 
> Thank you,
> 
> > Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
> > ---
> >  kernel/trace/trace_eprobe.c | 13 +++++--------
> >  1 file changed, 5 insertions(+), 8 deletions(-)
> > 
> > diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
> > index a0a704ba27db..d68d660dff7c 100644
> > --- a/kernel/trace/trace_eprobe.c
> > +++ b/kernel/trace/trace_eprobe.c
> > @@ -640,7 +640,7 @@ static int disable_eprobe(struct trace_eprobe *ep,
> >  static int enable_trace_eprobe(struct trace_event_call *call,
> >  			       struct trace_event_file *file)
> >  {
> > -	struct trace_probe *pos, *tp;
> > +	struct trace_probe *tp;
> >  	struct trace_eprobe *ep;
> >  	bool enabled;
> >  	int ret = 0;
> > @@ -662,8 +662,7 @@ static int enable_trace_eprobe(struct trace_event_call *call,
> >  	if (enabled)
> >  		return 0;
> >  
> > -	list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
> > -		ep = container_of(pos, struct trace_eprobe, tp);
> > +	list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
> >  		ret = enable_eprobe(ep, file);
> >  		if (ret)
> >  			break;
> > @@ -680,8 +679,7 @@ static int enable_trace_eprobe(struct trace_event_call *call,
> >  			 */
> >  			WARN_ON_ONCE(ret != -ENOMEM);
> >  
> > -			list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
> > -				ep = container_of(pos, struct trace_eprobe, tp);
> > +			list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
> >  				disable_eprobe(ep, file->tr);
> >  				if (!--cnt)
> >  					break;
> > @@ -699,7 +697,7 @@ static int enable_trace_eprobe(struct trace_event_call *call,
> >  static int disable_trace_eprobe(struct trace_event_call *call,
> >  				struct trace_event_file *file)
> >  {
> > -	struct trace_probe *pos, *tp;
> > +	struct trace_probe *tp;
> >  	struct trace_eprobe *ep;
> >  
> >  	tp = trace_probe_primary_from_call(call);
> > @@ -716,8 +714,7 @@ static int disable_trace_eprobe(struct trace_event_call *call,
> >  		trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
> >  
> >  	if (!trace_probe_is_enabled(tp)) {
> > -		list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
> > -			ep = container_of(pos, struct trace_eprobe, tp);
> > +		list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
> >  			disable_eprobe(ep, file->tr);
> >  		}
> >  	}
> > -- 
> > 2.39.2
> > 
> 
> 
> -- 
> Masami Hiramatsu (Google) <mhiramat@kernel.org>
Steven Rostedt Aug. 11, 2023, 5:46 p.m. UTC | #3 
On Fri, 11 Aug 2023 10:51:02 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:

> On Thu, 10 Aug 2023 19:32:04 +0900
> Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> 
> > On Thu, 10 Aug 2023 16:25:23 +0800
> > Chuang Wang <nashuiliang@gmail.com> wrote:
> >   
> > > Refer to the description in [1], we can skip "container_of()" following
> > > "list_for_each_entry()" by using "list_for_each_entry()" with
> > > "struct trace_eprobe" and "tp.list".
> > > 
> > > [1] https://lore.kernel.org/all/CAHk-=wjakjw6-rDzDDBsuMoDCqd+9ogifR_EE1F0K-jYek1CdA@mail.gmail.com/
> > >   
> > 
> > Good point. BTW, it is better to have 'for_each_eprobe(ep)' if it repeats 3 times.  
> 
> Wait, it is for each trace_eprobe on the trace_probe.
> 
> #define for_each_trace_eprobe_on_trace_probe(ep, _tp)
> 	list_for_each_entry(ep, trace_probe_probe_list(_tp), tp.list)
> 


Do we need it so verbose? Why can't it just be:

 #define for_each_trace_eprobe(ep, tp)

If you are worried about consistency with the for_each_trace_kprobe() then let's call it:

 #define for_each_trace_point_eprobe(ep, tp);

-- Steve
diff mbox series

Patch

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index a0a704ba27db..d68d660dff7c 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -640,7 +640,7 @@  static int disable_eprobe(struct trace_eprobe *ep,
 static int enable_trace_eprobe(struct trace_event_call *call,
 			       struct trace_event_file *file)
 {
-	struct trace_probe *pos, *tp;
+	struct trace_probe *tp;
 	struct trace_eprobe *ep;
 	bool enabled;
 	int ret = 0;
@@ -662,8 +662,7 @@  static int enable_trace_eprobe(struct trace_event_call *call,
 	if (enabled)
 		return 0;
 
-	list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
-		ep = container_of(pos, struct trace_eprobe, tp);
+	list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
 		ret = enable_eprobe(ep, file);
 		if (ret)
 			break;
@@ -680,8 +679,7 @@  static int enable_trace_eprobe(struct trace_event_call *call,
 			 */
 			WARN_ON_ONCE(ret != -ENOMEM);
 
-			list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
-				ep = container_of(pos, struct trace_eprobe, tp);
+			list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
 				disable_eprobe(ep, file->tr);
 				if (!--cnt)
 					break;
@@ -699,7 +697,7 @@  static int enable_trace_eprobe(struct trace_event_call *call,
 static int disable_trace_eprobe(struct trace_event_call *call,
 				struct trace_event_file *file)
 {
-	struct trace_probe *pos, *tp;
+	struct trace_probe *tp;
 	struct trace_eprobe *ep;
 
 	tp = trace_probe_primary_from_call(call);
@@ -716,8 +714,7 @@  static int disable_trace_eprobe(struct trace_event_call *call,
 		trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
 
 	if (!trace_probe_is_enabled(tp)) {
-		list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
-			ep = container_of(pos, struct trace_eprobe, tp);
+		list_for_each_entry(ep, trace_probe_probe_list(tp), tp.list) {
 			disable_eprobe(ep, file->tr);
 		}
 	}