* [PATCH] tracing: Use refcount for trace_event_file reference counter
@ 2024-07-26 18:42 Steven Rostedt
2024-07-29 14:49 ` Masami Hiramatsu
0 siblings, 1 reply; 4+ messages in thread
From: Steven Rostedt @ 2024-07-26 18:42 UTC (permalink / raw)
To: LKML, Linux trace kernel; +Cc: Masami Hiramatsu, Mathieu Desnoyers
From: Steven Rostedt <rostedt@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) <rostedt@goodmis.org>
---
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
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] tracing: Use refcount for trace_event_file reference counter
2024-07-26 18:42 [PATCH] tracing: Use refcount for trace_event_file reference counter Steven Rostedt
@ 2024-07-29 14:49 ` Masami Hiramatsu
2024-07-29 23:02 ` Steven Rostedt
0 siblings, 1 reply; 4+ messages in thread
From: Masami Hiramatsu @ 2024-07-29 14:49 UTC (permalink / raw)
To: Steven Rostedt
Cc: LKML, Linux trace kernel, Masami Hiramatsu, Mathieu Desnoyers
On Fri, 26 Jul 2024 14:42:08 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> From: Steven Rostedt <rostedt@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) <rostedt@goodmis.org>
Looks good to me.
Masami Hiramatsu (Google) <mhiramat@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) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] tracing: Use refcount for trace_event_file reference counter
2024-07-29 14:49 ` Masami Hiramatsu
@ 2024-07-29 23:02 ` Steven Rostedt
2024-07-30 0:02 ` Masami Hiramatsu
0 siblings, 1 reply; 4+ messages in thread
From: Steven Rostedt @ 2024-07-29 23:02 UTC (permalink / raw)
To: Masami Hiramatsu (Google); +Cc: LKML, Linux trace kernel, Mathieu Desnoyers
On Mon, 29 Jul 2024 23:49:24 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> On Fri, 26 Jul 2024 14:42:08 -0400
> Steven Rostedt <rostedt@goodmis.org> wrote:
>
> > From: Steven Rostedt <rostedt@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) <rostedt@goodmis.org>
>
> Looks good to me.
>
> Masami Hiramatsu (Google) <mhiramat@kernel.org>
Is that an ack or a review? ;-)
-- Steve
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] tracing: Use refcount for trace_event_file reference counter
2024-07-29 23:02 ` Steven Rostedt
@ 2024-07-30 0:02 ` Masami Hiramatsu
0 siblings, 0 replies; 4+ messages in thread
From: Masami Hiramatsu @ 2024-07-30 0:02 UTC (permalink / raw)
To: Steven Rostedt; +Cc: LKML, Linux trace kernel, Mathieu Desnoyers
On Mon, 29 Jul 2024 19:02:41 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:
> On Mon, 29 Jul 2024 23:49:24 +0900
> Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
>
> > On Fri, 26 Jul 2024 14:42:08 -0400
> > Steven Rostedt <rostedt@goodmis.org> wrote:
> >
> > > From: Steven Rostedt <rostedt@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) <rostedt@goodmis.org>
> >
> > Looks good to me.
> >
> > Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> Is that an ack or a review? ;-)
It was Ack,
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Sorry about that. I might be too sleep.
>
> -- Steve
>
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2024-07-26 18:42 [PATCH] tracing: Use refcount for trace_event_file reference counter Steven Rostedt
2024-07-29 14:49 ` Masami Hiramatsu
2024-07-29 23:02 ` Steven Rostedt
2024-07-30 0:02 ` Masami Hiramatsu
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