On Tue, Jan 12, 2016 at 08:28:44AM -0800, Paul E. McKenney wrote: > On Sun, Jan 10, 2016 at 04:16:32PM +0200, Michael S. Tsirkin wrote: > > From: Davidlohr Bueso <dave@xxxxxxxxxxxx> > > > > With commit b92b8b35a2e ("locking/arch: Rename set_mb() to smp_store_mb()") > > it was made clear that the context of this call (and thus set_mb) > > is strictly for CPU ordering, as opposed to IO. As such all archs > > should use the smp variant of mb(), respecting the semantics and > > saving a mandatory barrier on UP. > > > > Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx> > > Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> > > Cc: <linux-arch@xxxxxxxxxxxxxxx> > > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > > Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> > > Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> > > Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > > Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> > > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > > Cc: Tony Luck <tony.luck@xxxxxxxxx> > > Cc: dave@xxxxxxxxxxxx > > Link: http://lkml.kernel.org/r/1445975631-17047-3-git-send-email-dave@xxxxxxxxxxxx > > Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> > > Aside from a need for s/lcoking/locking/ in the subject line: > > Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Thanks! Though Ingo already put this in tip tree like this, and I need a copy in my tree to avoid breaking bisect, so I will probably keep it exactly the same to avoid confusion. > > --- > > arch/ia64/include/asm/barrier.h | 2 +- > > arch/powerpc/include/asm/barrier.h | 2 +- > > arch/s390/include/asm/barrier.h | 2 +- > > include/asm-generic/barrier.h | 2 +- > > 4 files changed, 4 insertions(+), 4 deletions(-) > > > > diff --git a/arch/ia64/include/asm/barrier.h b/arch/ia64/include/asm/barrier.h > > index df896a1..209c4b8 100644 > > --- a/arch/ia64/include/asm/barrier.h > > +++ b/arch/ia64/include/asm/barrier.h > > @@ -77,7 +77,7 @@ do { \ > > ___p1; \ > > }) > > > > -#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0) > > +#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0) > > > > /* > > * The group barrier in front of the rsm & ssm are necessary to ensure > > diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h > > index 0eca6ef..a7af5fb 100644 > > --- a/arch/powerpc/include/asm/barrier.h > > +++ b/arch/powerpc/include/asm/barrier.h > > @@ -34,7 +34,7 @@ > > #define rmb() __asm__ __volatile__ ("sync" : : : "memory") > > #define wmb() __asm__ __volatile__ ("sync" : : : "memory") > > > > -#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0) > > +#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0) > > > > #ifdef __SUBARCH_HAS_LWSYNC > > # define SMPWMB LWSYNC > > diff --git a/arch/s390/include/asm/barrier.h b/arch/s390/include/asm/barrier.h > > index d68e11e..7ffd0b1 100644 > > --- a/arch/s390/include/asm/barrier.h > > +++ b/arch/s390/include/asm/barrier.h > > @@ -36,7 +36,7 @@ > > #define smp_mb__before_atomic() smp_mb() > > #define smp_mb__after_atomic() smp_mb() > > > > -#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0) > > +#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0) > > > > #define smp_store_release(p, v) \ > > do { \ > > diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h > > index b42afad..0f45f93 100644 > > --- a/include/asm-generic/barrier.h > > +++ b/include/asm-generic/barrier.h > > @@ -93,7 +93,7 @@ > > #endif /* CONFIG_SMP */ > > > > #ifndef smp_store_mb > > -#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); mb(); } while (0) > > +#define smp_store_mb(var, value) do { WRITE_ONCE(var, value); smp_mb(); } while (0) > > #endif > > > > #ifndef smp_mb__before_atomic > > -- > > MST > >