On Fri, Oct 6, 2023 at 5:30 AM David Hildenbrand <david@xxxxxxxxxx> wrote: > > On 04.10.23 01:39, Lokesh Gidra wrote: > > On Tue, Oct 3, 2023 at 11:26 PM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > >> > >> On Tue, Oct 3, 2023 at 2:21 PM Peter Xu <peterx@xxxxxxxxxx> wrote: > >>> > >>> On Tue, Oct 03, 2023 at 11:08:07PM +0200, David Hildenbrand wrote: > >>>> Sorry I have to ask: has this ever been discussed on the list? I don't see > >>>> any pointers. If not, then probably the number of people that know about the > >>>> history can be counted with my two hands and that shouldn't be the basis for > >>>> making decisions. > >>> > >>> For example: > >>> > >>> https://lore.kernel.org/all/1425575884-2574-21-git-send-email-aarcange@xxxxxxxxxx/ > > Sorry, I had to process a family NMI the last couple of days. > > >> > >> There was another submission in 2019: > >> https://lore.kernel.org/all/cover.1547251023.git.blake.caldwell@xxxxxxxxxxxx/ > > It would be good to link them in the cover letter and shortly explain > why that wasn't merged back then (if there was any reason). Will do. I could not find the reason but will check again. > > >> > >> Though both times it did not generate much discussion. I don't have a > >> strong preference though MOVE sounds more generic to me TBH (it > >> specifies the operation rather than REMAP which hints on how that > >> operation is carried out). But again, I'm fine either way. > > > > That's a good point. IMHO, if in future we want to have the fallback > > implemented, then MOVE would be a more appropriate name than REMAP. > > > >> As for UFFDIO_MOVE_ZERO_COPY_ONLY vs UFFDIO_MOVE_MODE_ALLOW_COPY, I > >> find it weird that the default (the most efficient/desired) mode of > >> operation needs a flag. I would prefer to have no flag initially and > >> add UFFDIO_MOVE_MODE_ALLOW_COPY or whatever name is more appropriate > >> when/if we ever need it. Makes sense? > > > > Agreed! > > I agree. One could have UFFDIO_MOVE that is best-effort and documented > like that, and a to-be-named future extension that always works but > might be more expensive. > > > Ideally we'd have an interface that does not expose and/or rely on such > low-level information and simply always works, but getting that would > mean that we'd have to implement the fallback immediately ... so I guess > we'll have to expose a best-effort interface first. Sounds good. I'll try to post the next version early next week. Thanks for the input folks! > > -- > Cheers, > > David / dhildenb >
