On Fri, 29 Aug 2008, Gregory Haskins wrote: > Andi Kleen wrote: > >> Im running it on a x86_64 box as we speak. How can I tell if there is a > >> certain mode that is permitting this? > >> > > > > If the boot up says you're running with PMtimer then it uses the fallback > > (usually happens on pre Fam10h AMD boxes). A typical Intel box > > would use the faster ring 3 only TSC path and then explode with your > > change I bet. > > > > Or step with gdb through gettimeofday() and see if it does a syscall. > > > > -Andi > > > > It seems to be running fine with no indication it has fallen back. > Perhaps I need a certain workload to bring out the issue? Perhaps you never hit the slow path in userland. That's the only place it would write. Perhaps add a dummy static variable in the fast path, and write to it. See if that crashes you apps. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
