On Wed, Sep 18, 2019 at 02:59:08PM +0200, Thomas Hellström (VMware) wrote: > From: Thomas Hellstrom <thellst...@vmware.com> > > 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. > > The added file "as_dirty_helpers.c" is initially listed as maintained by > VMware under our DRM driver. If somebody would like it elsewhere, > that's of course no problem.
After quick glance, it looks a lot as rmap code duplication. Why not extend rmap_walk() interface instead to cover range of pages? > > Cc: Andrew Morton <a...@linux-foundation.org> > Cc: Matthew Wilcox <wi...@infradead.org> > Cc: Will Deacon <will.dea...@arm.com> > Cc: Peter Zijlstra <pet...@infradead.org> > Cc: Rik van Riel <r...@surriel.com> > Cc: Minchan Kim <minc...@kernel.org> > Cc: Michal Hocko <mho...@suse.com> > Cc: Huang Ying <ying.hu...@intel.com> > Cc: Souptick Joarder <jrdr.li...@gmail.com> > Cc: "Jérôme Glisse" <jgli...@redhat.com> > Cc: linux...@kvack.org > Cc: linux-ker...@vger.kernel.org > > Signed-off-by: Thomas Hellstrom <thellst...@vmware.com> > Reviewed-by: Ralph Campbell <rcampb...@nvidia.com> #v1 > --- > MAINTAINERS | 1 + > include/linux/mm.h | 13 +- > mm/Kconfig | 3 + > mm/Makefile | 1 + > mm/as_dirty_helpers.c | 392 ++++++++++++++++++++++++++++++++++++++++++ > 5 files changed, 409 insertions(+), 1 deletion(-) > create mode 100644 mm/as_dirty_helpers.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index c2d975da561f..b596c7cf4a85 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -5287,6 +5287,7 @@ T: git git://people.freedesktop.org/~thomash/linux > S: Supported > F: drivers/gpu/drm/vmwgfx/ > F: include/uapi/drm/vmwgfx_drm.h > +F: mm/as_dirty_helpers.c Emm.. No. Core MM functinality cannot belong to random driver. -- Kirill A. Shutemov
