Re: [PATCH 1/3] asm-generic/atomic64: Add support for ARCH_ATOMIC

[Peter Zijlstra]

On Wed, Nov 11, 2020 at 02:39:01PM +0100, Christophe Leroy wrote:
> Hello,
> 
> Le 11/11/2020 à 12:07, Nicholas Piggin a écrit :
> > This passes atomic64 selftest on ppc32 on qemu (uniprocessor only)
> > both before and after powerpc is converted to use ARCH_ATOMIC.
> 
> Can you explain what this change does and why it is needed ?

That certainly should've been in the Changelog. This enables atomic
instrumentation, see asm-generic/atomic-instrumented.h. IOW, it makes
atomic ops visible to K*SAN.