On Fri, Apr 15, 2011 at 12:29, Pavel Machek wrote: >> > > I believe the code is correct as is. >> > >> > that isnt what the code / documentation says. Âunless i'm reading them >> > wrong, both seem to indicate that the proposed patch is what we >> > actually want. >> >> The existing code is correct but it isn't optimal. >> >> wmb() and rmb() are heavy-duty operations, and you don't want to call >> them when they aren't needed. ÂThat's exactly what smp_wmb() and >> smp_rmb() are for -- they call wmb() and rmb(), but only in SMP >> kernels. >> >> Unless you need to synchronize with another processor (not necessarily >> a CPU, it could be something embedded within a device), you should >> always use smp_wmb() and smp_rmb() rather than wmb() and rmb(). > > Maybe; but this code is not performance critical and I believe being > obvious here is better... isnt it though ? especially when we talk about suspending/resuming on embedded systems to get more savings over just cpu idle ? we want that latency to be as low as possible. -mike _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
