2021-07-26 13:58:09

by Jason Wang

Subject: [PATCH] tracing: use WARN_ONCE

printk + WARN_ON_ONCE can be just WARN_ONCE.

Signed-off-by: Jason Wang <[email protected]>
---
kernel/trace/trace_output.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index a0bf446bb034..c06726b6d8b4 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -1574,9 +1574,8 @@ __init static int init_events(void)

ret = register_trace_event(event);
if (!ret) {
- printk(KERN_WARNING "event %d failed to register\n",
- event->type);
- WARN_ON_ONCE(1);
+ WARN_ONCE(1, "event %d failed to register\n",
+ event->type);
}
}

--
2.32.0

2021-07-26 15:04:42

by Steven Rostedt

Subject: Re: [PATCH] tracing: use WARN_ONCE

On Mon, 26 Jul 2021 21:56:35 +0800
Jason Wang <[email protected]> wrote:

> printk + WARN_ON_ONCE can be just WARN_ONCE.
>
> Signed-off-by: Jason Wang <[email protected]>
> ---
> kernel/trace/trace_output.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
> index a0bf446bb034..c06726b6d8b4 100644
> --- a/kernel/trace/trace_output.c
> +++ b/kernel/trace/trace_output.c
> @@ -1574,9 +1574,8 @@ __init static int init_events(void)
>
> ret = register_trace_event(event);
> if (!ret) {
> - printk(KERN_WARNING "event %d failed to register\n",
> - event->type);
> - WARN_ON_ONCE(1);
> + WARN_ONCE(1, "event %d failed to register\n",
> + event->type);
> }
> }
>

If you're going to change this, then nuke the conditional!

WARN_ONCE(!ret, "event %d failed to register\n", event->type);

-- Steve

2021-07-26 15:09:15

by Steven Rostedt

Subject: Re: [PATCH] tracing: use WARN_ONCE

On Mon, 26 Jul 2021 11:02:37 -0400
Steven Rostedt <[email protected]> wrote:

> > @@ -1574,9 +1574,8 @@ __init static int init_events(void)
> >
> > ret = register_trace_event(event);
> > if (!ret) {
> > - printk(KERN_WARNING "event %d failed to register\n",
> > - event->type);
> > - WARN_ON_ONCE(1);
> > + WARN_ONCE(1, "event %d failed to register\n",
> > + event->type);
> > }
> > }
> >
>
> If you're going to change this, then nuke the conditional!
>
> WARN_ONCE(!ret, "event %d failed to register\n", event->type);

Oh, and if you are making these types of changes, you need to
understand them. The string passed to WARN does not need the "\n" like
the printk() does.

WARN_ONCE(!ret, "event %d failed to register", event->type);

-- Steve