On Thu, 1 May 2025 11:27:12 -0400 Steven Rostedt <[email protected]> wrote:
> On Mon, 17 Mar 2025 17:03:16 +0900 > "Masami Hiramatsu (Google)" <[email protected]> wrote: > > > From: Masami Hiramatsu (Google) <[email protected]> > > > > As same as fprobe, register tracepoint stub function only when enabling > > tprobe events. The major changes are introducing a list of > > tracepoint_user and its lock, and tprobe_event_module_nb, which is > > another module notifier for module loading/unloading. By spliting the > > lock from event_mutex and a module notifier for trace_fprobe, it > > solved AB-BA lock dependency issue between event_mutex and > > tracepoint_module_list_mutex. > > > > Signed-off-by: Masami Hiramatsu (Google) <[email protected]> > > --- > > kernel/trace/trace_fprobe.c | 382 > > +++++++++++++++++++++++++------------------ > > 1 file changed, 218 insertions(+), 164 deletions(-) > > Is this patch still needed? It doesn't apply cleanly. This is a kind of performance optimization. Without this patch, tprobe always registers a stub function to the tracepoint. This *may* introduce an overhead, and it depends on how frequently the tracepoint is used. But I guess it is not noticable unless we create so many tprobes because the stub function is just a 'ret'. Thus this is not so hurry. Anyway, I will update it for for-next because this can clean up __tracepoint_probe_module_cb() logic too. Thank you, > > -- Steve -- Masami Hiramatsu (Google) <[email protected]>
