[RFT PATCH 13/13] tracing/kprobe: perf_event: Remove local kprobe event asynchronously

From: Masami Hiramatsu
Date: Thu Jan 16 2020 - 09:46:35 EST


Remove local kprobe event asynchronously. Note that this
can asynchronously remove a kprobe_event part, but the
perf_event needs to wait for all handlers finished before
removing the local kprobe event. So from the perf_event
(and eBPF) point of view, this shortens the trace termination
process a bit, but it still takes O(n) time to finish it.

To fix this issue, we need to change perf_event terminating
process by decoupling "disable events" and "destroy events"
as in ftrace.

Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---
kernel/trace/trace_kprobe.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index f7e0370b10ae..e8c4828c21ae 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1707,9 +1707,7 @@ void destroy_local_trace_kprobe(struct trace_event_call *event_call)
return;
}

- __unregister_trace_kprobe(tk);
-
- free_trace_kprobe(tk);
+ __unregister_trace_kprobe_async(tk);
}
#endif /* CONFIG_PERF_EVENTS */