On Thu, Dec 13, 2018 at 04:18:40PM -0500, Konrad Rzeszutek Wilk wrote: > .giant snip.. > > > + npinned = get_user_pages_fast(uaddr, npages, write, pages); > > > + if (npinned != npages) > > > + goto err; > > > + > > > > As I said I have doubts about the whole approach, but this > > implementation in particular isn't a good idea > > as it keeps the page around forever. > > So no THP, no NUMA rebalancing, userspace-controlled > > amount of memory locked up and not accounted for. > > > > Don't get me wrong it's a great patch in an ideal world. > > But then in an ideal world no barriers smap etc are necessary at all. > > So .. suggestions on how this could be accepted? As in other ways > where we still get vmap and the issues you mentioned are not troubling you? > > Thanks! I'd suggest leave vmap alone and find ways to speed up accesses that can fault. -- MST
