Re: What's cooking in git.git (Mar 2021, #08; Tue, 30)

[Elijah Newren <newren@gmail.com>]

Hi,

On Tue, Mar 30, 2021 at 5:17 PM Junio C Hamano <gitster@pobox.com> wrote:
> [New Topics]
> ...
> * en/ort-perf-batch-11 (2021-03-25) 7 commits
>  - merge-ort, diffcore-rename: employ cached renames when possible
>  - merge-ort: add helper functions for using cached renames
>  - merge-ort: preserve cached renames for the appropriate side
>  - merge-ort: avoid accidental API mis-use
>  - merge-ort: add code to check for whether cached renames can be reused
>  - merge-ort: populate caches of rename detection results
>  - merge-ort: add data structures for in-memory caching of rename detection
>  (this branch uses en/ort-perf-batch-10, en/ort-perf-batch-9 and en/ort-readiness.)

I was actually slightly surprised you picked this one up this early
given the other three in-flight.  I sent it out for review since folks
had reviewed the previous series and discussion on them had been quiet
for a while.

Please note that there is an issue with this series, as noted at
https://lore.kernel.org/git/CABPp-BGrevGj+xrm9bVcX5bp_WRv9cYP+g0hrAtjZK0u=sTHzQ@mail.gmail.com/,
so even if you merge the other series down, this one needs to be
re-rolled at least once first.  (I know you normally wouldn't merge
quickly, I just wanted to avoid an accidental merge to next based on
topic name similarity.)

> [Cooking]
...
> * en/ort-perf-batch-10 (2021-03-18) 8 commits
>  - diffcore-rename: determine which relevant_sources are no longer relevant
>  - merge-ort: record the reason that we want a rename for a file
>  - diffcore-rename: add computation of number of unknown renames
>  - diffcore-rename: check if we have enough renames for directories early on
>  - diffcore-rename: only compute dir_rename_count for relevant directories
>  - merge-ort: record the reason that we want a rename for a directory
>  - merge-ort, diffcore-rename: tweak dirs_removed and relevant_source type
>  - diffcore-rename: take advantage of "majority rules" to skip more renames
>  (this branch is used by en/ort-perf-batch-11 and en/ort-readiness; uses en/ort-perf-batch-9.)
>
>  I made a mistake of picking these up before they got sufficient
>  exposure to the reviewers and ended up a source of potential mess
>  when it turns out that any of the earlier ones need rewriting (I

Um...are you by chance conflating my comments linked above on
ort-perf-batch-11, the very latest series, with this series?  I
totally agree that ort-perf-batch-11 is in no state for building upon,
hasn't had sufficient review, and even if someone had reviewed it
quickly there hasn't been enough time to allow other reviewers to
chime in...but I haven't sent any subsequent series based on it.

>  probably should stop picking up nested series that exceeds reviewer
>  bandwidth), but how ready is this and subsequent topics?

I think ort-perf-batch-9, ort-perf-batch-10, and ort-readiness are all
ready to merge to next.  All have been reviewed by Stolee to his
satisfaction.  ort-readiness was also reviewed by Ævar (and used by
him in testing one of his series and helped him find a bug).

As noted above, ort-perf-batch-11 is not ready; please do not merge that one.

> * en/ort-readiness (2021-03-20) 13 commits
>  - Add testing with merge-ort merge strategy
>  - t6423: mark remaining expected failure under merge-ort as such
>  - Revert "merge-ort: ignore the directory rename split conflict for now"
>  - merge-recursive: add a bunch of FIXME comments documenting known bugs
>  - merge-ort: write $GIT_DIR/AUTO_MERGE whenever we hit a conflict
>  - t: mark several submodule merging tests as fixed under merge-ort
>  - merge-ort: implement CE_SKIP_WORKTREE handling with conflicted entries
>  - t6428: new test for SKIP_WORKTREE handling and conflicts
>  - merge-ort: support subtree shifting
>  - merge-ort: let renormalization change modify/delete into clean delete
>  - merge-ort: have ll_merge() use a special attr_index for renormalization
>  - merge-ort: add a special minimal index just for renormalization
>  - merge-ort: use STABLE_QSORT instead of QSORT where required
>  (this branch is used by en/ort-perf-batch-11; uses en/ort-perf-batch-10 and en/ort-perf-batch-9.)
>
>  Plug the ort merge backend throughout the rest of the system, and
>  start testing it as a replacement for the recursive backend.

As noted above, this series had two reviewers[1,2].

[1] https://lore.kernel.org/git/87pn09iu3j.fsf@evledraar.gmail.com/
[2] https://lore.kernel.org/git/4da61e15-a490-673a-ef15-800321ac9eea@gmail.com/

I'm not aware of any outstanding issues, the reviewers seemed happy as
of 2-3 weeks ago, and I haven't heard anyone else chime in so I'm
inclined to say this one is ready to merge to next.

> * en/ort-perf-batch-9 (2021-03-10) 8 commits
>  - diffcore-rename: avoid doing basename comparisons for irrelevant sources
>  - merge-ort: skip rename detection entirely if possible
>  - merge-ort: use relevant_sources to filter possible rename sources
>  - merge-ort: precompute whether directory rename detection is needed
>  - merge-ort: introduce wrappers for alternate tree traversal
>  - merge-ort: add data structures for an alternate tree traversal
>  - merge-ort: precompute subset of sources for which we need rename detection
>  - diffcore-rename: enable filtering possible rename sources
>  (this branch is used by en/ort-perf-batch-10, en/ort-perf-batch-11 and en/ort-readiness.)
>
>  The ort merge backend has been optimized by skipping irrelevant
>  renames.
>
>  Will merge to 'next'.

Thanks, sounds good.