Re: [PATCH 06/11] ftrace: add ftrace warn on to disable ftrace

Steven Rostedt
2008-10-22T19:20:36Z

On Wed, 22 Oct 2008, Andrew Morton wrote:
> > Index: linux-compile.git/kernel/trace/ftrace.c
> > ===================================================================
> > --- linux-compile.git.orig/kernel/trace/ftrace.c 2008-10-22 13:17:29.000000000 -0400
> > +++ linux-compile.git/kernel/trace/ftrace.c 2008-10-22 13:20:11.000000000 -0400
> > @@ -32,6 +32,24 @@
> >
> > #include "trace.h"
> >
> > +#define FTRACE_WARN_ON(cond) \
> > + do { \
> > + if (unlikely(cond)) { \
> > + WARN_ON(1); \
> > + ftrace_kill(); \
> > + } \
> > + } while (0)
>
> This could be coded as
>
> if (WARN_ON(cond))
> ftrace_kill();

Ah, I didn't realize that WARN_ON returned the value of the condition.
Will update in v2.

-- Steve

>
> > +#define FTRACE_WARN_ON_ONCE(cond) \
> > + do { \
> > + static int once; \
> > + if (unlikely(cond) && !once) { \
> > + once++; \
> > + WARN_ON(1); \
> > + ftrace_kill(); \
> > + } \
> > + } while (0)
>
>
> if (WARN_ON_ONCE(cond))
> ftrace_kill();
>
>
>
>