[PATCH v3] tracing/eprobe: Iterate trace_eprobe directly

[PATCH v3] tracing/eprobe: Iterate trace_eprobe directly

[Chuang Wang]

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".

Also, this patch defines "for_each_trace_eprobe_tp" to simplify the code
of the same logic.

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

Signed-off-by: Chuang Wang <nashuiliang@gmail.com>
---
v2 -> v3:
- use "for_each_trace_eprobe_tp" instead of "for_each_trace_eprobe_on_trace_probe"

v1 -> v2:
- add "for_each_trace_eprobe_on_trace_probe" as suggested by Masami

v0 -> v1:
- remove "Fixes" in the commit information.

 kernel/trace/trace_eprobe.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
index a0a704ba27db..6a024b5912e2 100644
--- a/kernel/trace/trace_eprobe.c
+++ b/kernel/trace/trace_eprobe.c
@@ -41,6 +41,10 @@ struct eprobe_data {
 	struct trace_eprobe	*ep;
 };
 
+
+#define for_each_trace_eprobe_tp(ep, _tp) \
+	list_for_each_entry(ep, trace_probe_probe_list(_tp), tp.list)
+
 static int __trace_eprobe_create(int argc, const char *argv[]);
 
 static void trace_event_probe_cleanup(struct trace_eprobe *ep)
@@ -640,7 +644,7 @@ 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 +666,7 @@ 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);
+	for_each_trace_eprobe_tp(ep, tp) {
 		ret = enable_eprobe(ep, file);
 		if (ret)
 			break;
@@ -680,8 +683,7 @@ 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);
+			for_each_trace_eprobe_tp(ep, tp) {
 				disable_eprobe(ep, file->tr);
 				if (!--cnt)
 					break;
@@ -699,7 +701,7 @@ 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);
@@ -716,10 +718,8 @@ 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);
+		for_each_trace_eprobe_tp(ep, tp)
 			disable_eprobe(ep, file->tr);
-		}
 	}
 
  out:
-- 
2.39.2

Re: [PATCH v3] tracing/eprobe: Iterate trace_eprobe directly

[Masami Hiramatsu]

On Tue, 22 Aug 2023 10:24:33 +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".
> 
> Also, this patch defines "for_each_trace_eprobe_tp" to simplify the code
> of the same logic.
> 
> [1] https://lore.kernel.org/all/CAHk-=wjakjw6-rDzDDBsuMoDCqd+9ogifR_EE1F0K-jYek1CdA@mail.gmail.com/
> 
> Signed-off-by: Chuang Wang <nashuiliang@gmail.com>

Thanks, this looks good to me.

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

> ---
> v2 -> v3:
> - use "for_each_trace_eprobe_tp" instead of "for_each_trace_eprobe_on_trace_probe"
> 
> v1 -> v2:
> - add "for_each_trace_eprobe_on_trace_probe" as suggested by Masami
> 
> v0 -> v1:
> - remove "Fixes" in the commit information.
> 
>  kernel/trace/trace_eprobe.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c
> index a0a704ba27db..6a024b5912e2 100644
> --- a/kernel/trace/trace_eprobe.c
> +++ b/kernel/trace/trace_eprobe.c
> @@ -41,6 +41,10 @@ struct eprobe_data {
>  	struct trace_eprobe	*ep;
>  };
>  
> +
> +#define for_each_trace_eprobe_tp(ep, _tp) \
> +	list_for_each_entry(ep, trace_probe_probe_list(_tp), tp.list)
> +
>  static int __trace_eprobe_create(int argc, const char *argv[]);
>  
>  static void trace_event_probe_cleanup(struct trace_eprobe *ep)
> @@ -640,7 +644,7 @@ 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 +666,7 @@ 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);
> +	for_each_trace_eprobe_tp(ep, tp) {
>  		ret = enable_eprobe(ep, file);
>  		if (ret)
>  			break;
> @@ -680,8 +683,7 @@ 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);
> +			for_each_trace_eprobe_tp(ep, tp) {
>  				disable_eprobe(ep, file->tr);
>  				if (!--cnt)
>  					break;
> @@ -699,7 +701,7 @@ 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);
> @@ -716,10 +718,8 @@ 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);
> +		for_each_trace_eprobe_tp(ep, tp)
>  			disable_eprobe(ep, file->tr);
> -		}
>  	}
>  
>   out:
> -- 
> 2.39.2
> 


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>