On Tue, Apr 27, 2021 at 01:29:14PM -0700, Axel Rasmussen wrote: > On Tue, Apr 27, 2021 at 11:03 AM Peter Xu <peterx@xxxxxxxxxx> wrote: > > > > On Tue, Apr 27, 2021 at 09:57:16AM -0700, Axel Rasmussen wrote: > > > I'd prefer to keep them separate, as they are not tiny patches (they > > > are roughly +200/-150 each). And, they really are quite independent - > > > at least in the sense that I can reorder them via rebase with no > > > conflicts, and the code builds at each commit in either orientation. I > > > think this implies they're easier to review separately, rather than > > > squashed. > > > > > > I don't have a strong feeling about the order. I slightly prefer > > > swapping them compared to this v4 series: first introduce minor > > > faults, then introduce CONTINUE. > > > > > > Since Peter also has no strong opinion, and Hugh it sounds like you > > > prefer it the other way around, I'll swap them as we had in some > > > previous version of this series: first introduce minor faults, then > > > introduce CONTINUE. > > > > Yes I have no strong opinion, but that's probably the least I prefer. :-) > > > > Because you'll declare UFFD_FEATURE_MINOR_SHMEM and enable this feature without > > the feature being completely implemented (without UFFDIO_CONTINUE, it's not > > complete since no one will be able to resolve that minor fault). > > > > Not a big deal anyway, but since we're at it... Basically I think three things > > to do for minor shmem support: > > > > (1) UFFDIO_CONTINUE (resolving path) > > (2) Handle fault path for shmem minor fault (faulting path) > > (3) Enablement of UFFD_FEATURE_MINOR_SHMEM (from which point, user can detect > > and enable it) > > > > I have no preference on how you'd like to merge these steps (right now you did > > 1 first, then 2+3 later; or as Hugh suggested do 1+2+3 together), but I'd still > > hope item 3 should always be the last, if possible... > > In that case, I'll split the patch which adds the faulting path in > two: add the faulting path hook and registration mode, and then in a > separate commit advertise the feature flag as available. > > Then I'll order them like so, which I think is the order Hugh finds > more natural: > 1. MInor fault registration / faulting path > 2. CONTINUE ioctl to resolve the faults > 3. Advertise the feature as supported > > Sound okay? Good to me, thanks Axel. -- Peter Xu
