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 <[email protected]>
---
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
On Thu, 10 Aug 2023 16:25:23 +0800
Chuang Wang <[email protected]> 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 <[email protected]>
> ---
> 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) <[email protected]>
On Thu, 10 Aug 2023 19:32:04 +0900
Masami Hiramatsu (Google) <[email protected]> wrote:
> On Thu, 10 Aug 2023 16:25:23 +0800
> Chuang Wang <[email protected]> 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 <[email protected]>
> > ---
> > 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) <[email protected]>
--
Masami Hiramatsu (Google) <[email protected]>
On Fri, 11 Aug 2023 10:51:02 +0900
Masami Hiramatsu (Google) <[email protected]> wrote:
> On Thu, 10 Aug 2023 19:32:04 +0900
> Masami Hiramatsu (Google) <[email protected]> wrote:
>
> > On Thu, 10 Aug 2023 16:25:23 +0800
> > Chuang Wang <[email protected]> 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