Am 15.01.2015 um 20:38 schrieb Oleg Nesterov: > On 01/15, Christian Borntraeger wrote: >> >> --- a/arch/x86/include/asm/spinlock.h >> +++ b/arch/x86/include/asm/spinlock.h >> @@ -186,7 +186,7 @@ static inline void arch_spin_unlock_wait(arch_spinlock_t >> *lock) >> __ticket_t head = ACCESS_ONCE(lock->tickets.head); >> >> for (;;) { >> - struct __raw_tickets tmp = ACCESS_ONCE(lock->tickets); >> + struct __raw_tickets tmp = READ_ONCE(lock->tickets); > > Agreed, but what about another ACCESS_ONCE() above? > > Oleg. >
tickets.head is a scalar type, so ACCESS_ONCE does work fine with gcc 4.6/4.7. My goal was to convert all accesses on non-scalar types as until "kernel: tighten rules for ACCESS ONCE" is merged because anything else would be a Whac-a-mole like adventure (I learned that during the last round in next: all conversions in this series fix up changes made during this merge window) We probably going to do a bigger bunch of bulk conversion later on when "kernel: tighten rules for ACCESS ONCE" prevents new problems. Makes sense? Christian -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html