[PATCH] powerpc/le: enable RTAS events support

Stewart Smith stewart at linux.vnet.ibm.com
Tue Apr 1 09:49:41 EST 2014


Benjamin Herrenschmidt <benh at kernel.crashing.org> writes:
> On Mon, 2014-03-31 at 09:27 +1100, Stewart Smith wrote:
>> Greg Kurz <gkurz at linux.vnet.ibm.com> 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..

A quick grep didn't show up anything that looked like on disk
formats... at least for anything I care about :)

Maybe I've spent too long writing code for more than one compiler :)



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