Re: [S390] Use generic bug.

[Heiko Carstens <heiko.carstens@de.ibm.com>]

On Mon, Mar 05, 2007 at 02:56:29PM -0800, David Miller wrote:
> From: Martin Schwidefsky <schwidefsky@de.ibm.com>
> Date: Mon, 5 Mar 2007 23:43:54 +0100
> 
> > +	if (__builtin_constant_p(__ret_warn_on)) {	\
> > +		if (__ret_warn_on)			\
> > +			__EMIT_BUG(BUGFLAG_WARNING);	\
> 
> I see we'll have this construct on powerpc, parisc and now s390.
> 
> But if it's going to trigger essentially at compile time, I
> think it's much better to BUILD_BUG_ON() in this case instead
> of counting on the code path to actually run and the user to
> notice and report the kernel log message.

So something like WARN_ON(1) won't compile, but BUG_ON(1) still
would? Seems odd to me.
Also since there is nothing like WARN(), you have to use WARN_ON(1).
Btw.: sparc64 has plenty of these ;)

I would prefer to have something like a per arch defined WARN()
and a common code WARN_ON() like we have it already for BUG_ON().
Then I would agree: if WARN_ON() is used with a constant the build
should fail. Just to tell the author that he did something wrong
or simply should use WARN(). And of course the existing BUG_ON()
could be converted as well.