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. :) >> >> 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
