On Tue, Aug 13, 2019 at 05:56:31PM -0700, John Hubbard wrote: > On 8/13/19 5:51 PM, John Hubbard wrote: > > On 8/13/19 2:08 PM, Ira Weiny wrote: > >> On Mon, Aug 12, 2019 at 05:07:32PM -0700, John Hubbard wrote: > >>> On 8/12/19 4:49 PM, Ira Weiny wrote: > >>>> On Sun, Aug 11, 2019 at 06:50:44PM -0700, john.hubbard@xxxxxxxxx wrote: > >>>>> From: John Hubbard <jhubbard@xxxxxxxxxx> > >>> ... > >> Finally, I struggle with converting everyone to a new call. It is more > >> overhead to use vaddr_pin in the call above because now the GUP code is going > >> to associate a file pin object with that file when in ODP we don't need that > >> because the pages can move around. > > > > What if the pages in ODP are file-backed? > > > > oops, strike that, you're right: in that case, even the file system case is covered. > Don't mind me. :) Ok so are we agreed we will drop the patch to the ODP code? I'm going to keep the FOLL_PIN flag and addition in the vaddr_pin_pages. Ira > > >> > >> This overhead may be fine, not sure in this case, but I don't see everyone > >> wanting it. > > So now I see why you said that, but I will note that ODP hardware is rare, > and will likely remain rare: replayable page faults require really special > hardware, and after all this time, we still only have CPUs, GPUs, and the > Mellanox cards that do it. > > That leaves a lot of other hardware to take care of. > > thanks, > -- > John Hubbard > NVIDIA >
