On Fri, 26 Jul 2024 14:42:08 -0400
Steven Rostedt <rost...@goodmis.org> wrote:
> From: Steven Rostedt <rost...@goodmis.org>
>
> Instead of using an atomic counter for the trace_event_file reference
> counter, use the refcount interface. It has various checks to make sure
> the reference counting is correct, and will warn if it detects an error
> (like refcount_inc() on '0').
>
> Signed-off-by: Steven Rostedt (Google) <rost...@goodmis.org>
Looks good to me.
Masami Hiramatsu (Google) <mhira...@kernel.org>
Thanks,
> ---
> include/linux/trace_events.h | 2 +-
> kernel/trace/trace_events.c | 8 ++++----
> 2 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
> index 9df3e2973626..fed58e54f15e 100644
> --- a/include/linux/trace_events.h
> +++ b/include/linux/trace_events.h
> @@ -680,7 +680,7 @@ struct trace_event_file {
> * caching and such. Which is mostly OK ;-)
> */
> unsigned long flags;
> - atomic_t ref; /* ref count for opened files */
> + refcount_t ref; /* ref count for opened files */
> atomic_t sm_ref; /* soft-mode reference counter */
> atomic_t tm_ref; /* trigger-mode reference counter */
> };
> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> index 852643d957de..81ade9ddcbe5 100644
> --- a/kernel/trace/trace_events.c
> +++ b/kernel/trace/trace_events.c
> @@ -992,18 +992,18 @@ static void remove_subsystem(struct trace_subsystem_dir
> *dir)
>
> void event_file_get(struct trace_event_file *file)
> {
> - atomic_inc(&file->ref);
> + refcount_inc(&file->ref);
> }
>
> void event_file_put(struct trace_event_file *file)
> {
> - if (WARN_ON_ONCE(!atomic_read(&file->ref))) {
> + if (WARN_ON_ONCE(!refcount_read(&file->ref))) {
> if (file->flags & EVENT_FILE_FL_FREED)
> kmem_cache_free(file_cachep, file);
> return;
> }
>
> - if (atomic_dec_and_test(&file->ref)) {
> + if (refcount_dec_and_test(&file->ref)) {
> /* Count should only go to zero when it is freed */
> if (WARN_ON_ONCE(!(file->flags & EVENT_FILE_FL_FREED)))
> return;
> @@ -2999,7 +2999,7 @@ trace_create_new_event(struct trace_event_call *call,
> atomic_set(&file->tm_ref, 0);
> INIT_LIST_HEAD(&file->triggers);
> list_add(&file->list, &tr->events);
> - event_file_get(file);
> + refcount_set(&file->ref, 1);
>
> return file;
> }
> --
> 2.43.0
>
--
Masami Hiramatsu (Google) <mhira...@kernel.org>
