On Wed, Jun 12, 2019 at 08:42:37AM +0200, Thomas Hellström (VMware) wrote: > From: Thomas Hellstrom <thellstrom@xxxxxxxxxx> > > Add two utilities to a) write-protect and b) clean all ptes pointing into > a range of an address space. > The utilities are intended to aid in tracking dirty pages (either > driver-allocated system memory or pci device memory). > The write-protect utility should be used in conjunction with > page_mkwrite() and pfn_mkwrite() to trigger write page-faults on page > accesses. Typically one would want to use this on sparse accesses into > large memory regions. The clean utility should be used to utilize > hardware dirtying functionality and avoid the overhead of page-faults, > typically on large accesses into small memory regions. Please use EXPORT_SYMBOL_GPL, just like for apply_to_page_range and friends. Also in general new core functionality like this should go along with the actual user, we don't need to repeat the hmm disaster.
