On Tue, Mar 28, 2017 at 02:35:13PM -0700, Matthew Wilcox wrote:
> On Tue, Mar 28, 2017 at 06:15:41PM +0200, Dmitry Vyukov wrote:
> > The new header allows to wrap per-arch atomic operations
> > and add common functionality to all of them.
>
> Why a new header instead of putting this in linux/atomic.h?
The idea was that doing it this way allowed architectures to switch over
to the arch_* naming without a flag day. Currently this only matters for
KASAN, which is only supported by a couple of architectures (arm64,
x86).
I seem to recall that there was an issue that prevented us from solving
this with ifdeffery early in linux/atomic.h like:
#ifdef arch_op
#define op(...) ({ \
kasna_whatever(...) \
arch_op(...) \
})
#endif
... but I can't recall specifically what it was.
Thanks,
Mark.
