Derek Murray wrote: > I take the blame for that one. I added the hook because, if a process > were to die whilst holding one or more grants, there were no hooks that > would make it possible to carry out the grant-unmap. All existing hooks > on either the device or the VMA were called *after* the PTEs were cleared. Hmm. What exactly is the issue here? This is about *userspace* mappings, right? As far as I can see from a quick scan there of the code is an additional kernel space mapping for the grants and the userspace mapping is optional. I don't see any problems with userspace mapping going away without *instant* notification. Cleaning up a bit later, called from the file_ops->release callback maybe, should work ok. The problem I see with the additional vm_ops callback is that I suspect you'll have to come up with some *very* good arguments to get it accepted by the VM (as in "virtual memory") folks and merged mainline. > It gets better, though. The same hook is used in the version of blktap > in linux-2.6.18-xen (not, as far as I can see, in the sparse tree for > xen-3.1-testing): Oh, I'm thinking more in the direction of killing blktap altogether in favor of a pure userspace implementation on top of gntdev. cheers, Gerd _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
