Re: [PATCH 5/5] ring-buffer: fix printk output

Andrew Morton
2009-04-29T05:58:20Z

On Wed, 29 Apr 2009 07:43:59 +0200 Ingo Molnar <mingo@elte.hu> wrote:

>
> * Andrew Morton <akpm@linux-foundation.org> wrote:
>
> > On Wed, 29 Apr 2009 00:48:19 -0400 Steven Rostedt <rostedt@goodmis.org> wrote:
> >
> > > - printk_once(KERN_WARNING "Tracing recursion: depth[%d]:"
> > > + printk_once(KERN_WARNING "Tracing recursion: depth[%ld]:"
> >
> > hrmph. I didn't know that printk_once() existed, and I should
> > have known. I wonder how many other people don't know.
>
> Was posted to linux-next@vger.kernel.org.

Well no wonder I didn't know about it.

> > Should it use unlikely()?
>
> Not really. Any printk_once() usage site is an 'unlikely' branch
> already in most cases. Double unlikely just spreads the instructions
> needlessly. The condition that _leads_ to a printk_once() should be
> an unlikely().
>

OK.