On Thu, 24 Jul 2014 16:35:39 +0200 Joerg Roedel <joro@xxxxxxxxxx> wrote: > From: Joerg Roedel <jroedel@xxxxxxx> > > This notifier closes an important gap with the current > invalidate_range_start()/end() notifiers. The _start() part > is called when all pages are still mapped while the _end() > notifier is called when all pages are potentially unmapped > and already freed. > > This does not allow to manage external (non-CPU) hardware > TLBs with MMU-notifiers because there is no way to prevent > that hardware will establish new TLB entries between the > calls of these two functions. But this is a requirement to > the subsytem that implements these existing notifiers. > > To allow managing external TLBs the MMU-notifiers need to > catch the moment when pages are unmapped but not yet freed. > This new notifier catches that moment and notifies the > interested subsytem when pages that were unmapped are about > to be freed. The new notifier will only be called between > invalidate_range_start()/end(). So if we were actually sharing page tables, we should be able to make start/end no-ops and just use this new callback, assuming we didn't need to do any other serialization or debug stuff, right? Seems like a good addition, and saves us a bunch of trouble... Thanks, -- Jesse Barnes, Intel Open Source Technology Center -- 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>