On Mon, Jun 16, 2008 at 6:05 PM, Matthew Wilcox <matthew@xxxxxx> wrote: > The only users of __ldcw() are in spinlock.h which has the mb()s in > place. I don't think there's a problem here. Given: mb() __ldcw(a) mb() What stops the compiler from doing? mb() *stack_slot = *a reg1 = *stack_slot reg2 = __ldcw(reg1) *a = *stack_slot mb() Memory is consistent before and after the memory barriers, but the operation is not atomic? While this seems stupid, the compile may create a memory temporary to shuffle things around. Cheers, Carlos. -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
