[PATCH] tracing: kprobe-event: Return directly when dyn_event_list is empty

[sunliming@linux.dev]

From: sunliming <sunliming@kylinos.cn>

In enable_boot_kprobe_events(), it returns directly when dyn_event_list is
empty, thereby reducing the function's execution time. This function may
otherwise wait for the event_mutex lock for tens of milliseconds on certain
machines, which is unnecessary when dyn_event_list is empty.

Signed-off-by: sunliming <sunliming@kylinos.cn>
---
 kernel/trace/trace_kprobe.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 9953506370a5..d89a403c99d4 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1982,6 +1982,9 @@ static __init void enable_boot_kprobe_events(void)
 	struct trace_kprobe *tk;
 	struct dyn_event *pos;
 
+	if (list_empty(&dyn_event_list))
+		return;
+
 	guard(mutex)(&event_mutex);
 	for_each_trace_kprobe(tk, pos) {
 		list_for_each_entry(file, &tr->events, list)
-- 
2.25.1