On Wed, 3 Sep 2014, Paul E. McKenney wrote: > You would prefer that I instead allocated an NR_CPUS-sized array?
Well, a shared data structure would be cleaner in general but there are certainly other approaches. But lets focus on the dynticks_idle case we are discussing here rather than tackle the more difficult other atomics. What is checked in the loop over the remote cpus is the dynticks_idle value plus dynticks_idle_jiffies. So it seems that memory ordering is only used to ensure that the jiffies are seen correctly. In that case both the dynticks_idle and dynticks_idle_jiffies could be placed in one 64 bit value. If this is stored and retrieved as one then there is no issue with ordering anymore and the barriers would no longer be needed. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
