On Thu, Dec 19, 2013 at 06:25:35PM +0100, Peter Zijlstra wrote: > On Thu, Dec 19, 2013 at 06:07:41PM +0100, Ingo Molnar wrote: > > Likewise, having a barrier before the MONITOR looks sensible as well. > > I again have to disagree, one would expect monitor to flush all that is > required to start the monitor -- and it actually does so. As is > testified by this extra CLFLUSH being called a bug workaround. SDM states that MONITOR is ordered like a LOAD, and a LOAD cannot pass a previous STORE to the same address. That said; there's enough holes in there to swim a titanic through, seeing how MONITOR stares at an entire cacheline and LOAD/STORE order is specified on location, whatever that means. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html