On Sun, May 6, 2018, at 8:11 PM, Ingo Molnar wrote: > > * Boqun Feng <boqun.f...@gmail.com> wrote: > > > > The only change I made beyond a trivial build fix is that I also added > > > the release > > > atomics variants explicitly: > > > > > > +#define atomic_cmpxchg_release(v, o, n) \ > > > + cmpxchg_release(&((v)->counter), (o), (n)) > > > +#define atomic64_cmpxchg_release(v, o, n) \ > > > + cmpxchg_release(&((v)->counter), (o), (n)) > > > > > > It has passed a PowerPC cross-build test here, but no runtime tests. > > > > > > > Do you have the commit at any branch in tip tree? I could pull it and > > cross-build and check the assembly code of lib/atomic64_test.c, that way > > I could verify whether we mess something up. > > > > > Does this patch look good to you? > > > > > > > Yep! > > Great - I have pushed the commits out into the locking tree, they can be > found in: > > git fetch git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git > locking/core >
Thanks! My compile test told me that we need to remove the definitions of atomic_xchg and atomic64_xchg in ppc's asm/atomic.h: they are now duplicate, and will prevent the generation of _release and _acquire in the new logic. If you need a updated patch for this from me, I could send later today. (I don't have a handy environment for patch sending now, so...) Other than this, the modification looks fine, the lib/atomic64_test.c generated the same asm before and after the patches. Regards, Boqun > The PowerPC preparatory commit from you is: > > 0476a632cb3a: locking/atomics/powerpc: Move cmpxchg helpers to asm/ > cmpxchg.h and define the full set of cmpxchg APIs > > Thanks, > > Ingo
