On Sat, Nov 17, 2012 at 06:56:10AM -0800, Linus Torvalds wrote: > I wonder how we could actually test for it. We'd have to have some > per-cpu page-fault address check (along with a generation count on the > mm or similar). I doubt we'd figure out anything that works reliably > and efficiently and would actually show any problems (plus we would > have no way to ever know we even got the code right, since presumably > we'd never find hardware that actually shows the behavior we'd be > looking for..) Hmm, touching some wrong page through the stale TLB entry could be a pretty nasty issue to debug. But you're probably right: how does one test cheaply whether a PTE just got kicked out of the TLB? Maybe mark it not-present but this would force a rewalk in the case when it is shared, which is penalty we don't want to pay. Oh well... -- Regards/Gruss, Boris. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>