Subject: Re: [PATCH] powerpc/le: enable RTAS events support

From: Benjamin Herrenschmidt <[email-masked]>
Date: Mon, 31 Mar 2014 22:56:13 +1100

On Mon, 2014-03-31 at 09:27 +1100, Stewart Smith wrote:
> Greg Kurz <[email-masked]> writes:
> >  struct rtas_error_log {
> > +#ifdef __BIG_ENDIAN__
> > +	/* Byte 0 */
> >  	unsigned long version:8;		/* Architectural version */
> > +	/* Byte 1 */
> 
> I think it would be great if we got rid of the usage of bitfields. As
> soon as the mood of the compiler changes, this code is going to break.

 ... as would a whole pile of kernel code including filesystems :)

Now, don't get me wrong, I hate bitfields as much as you do for the same
reasons. However (unfortunately ?) we've somewhat painted ourselves into
a corner here in kernel-land and I suspect gcc would have a very hard
time changing the format considering how many people did just the same
we did.

Now if we were a userspace program, I would still insist on fixing it on
the ground on not depending on gcc but this is the kernel ... we have
more gcc'isms than spots on the face of a 14 yrs old..

Cheers,
Ben.