From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
To: Chuang Wang <nashuiliang@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH] tracing/eprobe: Iterate trace_eprobe directly
Date: Thu, 10 Aug 2023 19:32:04 +0900 [thread overview]
Message-ID: <20230810193204.cae5808af79bbcc80b88ff77@kernel.org> (raw)
In-Reply-To: <20230810082523.244397-1-nashuiliang@gmail.com>
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) <mhiramat@kernel.org>
next prev parent reply other threads:[~2023-08-10 10:32 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-10 8:25 Chuang Wang
2023-08-10 10:32 ` Masami Hiramatsu [this message]
2023-08-11 1:51 ` Masami Hiramatsu
2023-08-11 17:46 ` Steven Rostedt
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