On Thu, Jul 4, 2019 at 12:59 PM Jason Gunthorpe <jgg@xxxxxxxxxxxx> wrote: > > On Thu, Jul 04, 2019 at 11:53:24AM -0700, Andrew Morton wrote: > > On Wed, 26 Jun 2019 20:35:51 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > Let me know and I can help orchestate this. > > > > > > Well. Whatever works. In this situation I'd stage the patches after > > > linux-next and would merge them up after the prereq patches have been > > > merged into mainline. Easy. > > > > All right, what the hell just happened? > > Christoph's patch series for the devmap & hmm rework finally made it > into linux-next, sorry, it took quite a few iterations on the list to > get all the reviews and tests, and figure out how to resolve some > other conflicting things. So it just made it this week. > > Recall, this is the patch series I asked you about routing a few weeks > ago, as it really exceeded the small area that hmm.git was supposed to > cover. I think we are both caught off guard how big the conflict is! > > > A bunch of new material has just been introduced into linux-next. > > I've partially unpicked the resulting mess, haven't dared trying to > > compile it yet. To get this far I'll need to drop two patch series > > and one individual patch: > > > mm-clean-up-is_device__page-definitions.patch > > mm-introduce-arch_has_pte_devmap.patch > > arm64-mm-implement-pte_devmap-support.patch > > arm64-mm-implement-pte_devmap-support-fix.patch > > This one we discussed, and I thought we agreed would go to your 'stage > after linux-next' flow (see above). I think the conflict was minor > here. > > > mm-sparsemem-introduce-struct-mem_section_usage.patch > > mm-sparsemem-introduce-a-section_is_early-flag.patch > > mm-sparsemem-add-helpers-track-active-portions-of-a-section-at-boot.patch > > mm-hotplug-prepare-shrink_zone-pgdat_span-for-sub-section-removal.patch > > mm-sparsemem-convert-kmalloc_section_memmap-to-populate_section_memmap.patch > > mm-hotplug-kill-is_dev_zone-usage-in-__remove_pages.patch > > mm-kill-is_dev_zone-helper.patch > > mm-sparsemem-prepare-for-sub-section-ranges.patch > > mm-sparsemem-support-sub-section-hotplug.patch > > mm-document-zone_device-memory-model-implications.patch > > mm-document-zone_device-memory-model-implications-fix.patch > > mm-devm_memremap_pages-enable-sub-section-remap.patch > > libnvdimm-pfn-fix-fsdax-mode-namespace-info-block-zero-fields.patch > > libnvdimm-pfn-stop-padding-pmem-namespaces-to-section-alignment.patch > > Dan pointed to this while reviewing CH's series and said the conflicts > would be manageable, but they are certainly larger than I expected! > > This series is the one that seems to be the really big trouble. I > already checked all the other stuff that Stephen resolved, and it > looks OK and managable. Just this one conflict with kernel/memremap.c > is beyond me. > > What approach do you want to take to go forward? Here are some thoughts: > > CH has said he is away for the long weekend, so the path that involves > the fewest people is if Dan respins the above on linux-next and it > goes later with the arm patches above, assuming defering it for now > has no other adverse effects on -mm. > > Pushing CH's series to -mm would need a respin on top of Dan's series > above and would need to carry along the whole hmm.git (about 44 > patches). Signs are that this could be managed with the code currently > in the GPU trees. > > If we give up on CH's series the hmm.git will not have conflicts, > however we just kick the can to the next merge window where we will be > back to having to co-ordinate amd/nouveau/rdma git trees and -mm's > patch workflow - and I think we will be worse off as we will have > totally given up on a git based work flow for this. :( I think the problem would be resolved going forward post-v5.3 since we won't have two tress managing kernel/memremap.c. This cycle however there is a backlog of kernel/memremap.c changes in -mm.
