> This set tries to speed up git status (and other commands which examine the tree state) for repositories with many submodules.
I built these patches on top of master from d6fd04375f (The twelfth batch, 2024-03-28), and that went smoothly. However, I used hyperfine to benchmark the changes in a repo of mine with many submodules (which I have used as a case study for the performance before [1]), and I don’t notice any change:
λ hyperfine 'git status' ~c/git/git-status 'git status --ignore-submodules=all' '~/code/git/git-status --ignore-submodules=all'
Benchmark 1: git status
Time (mean ± σ): 977.8 ms ± 3.4 ms [User: 415.4 ms, System: 460.2 ms]
Range (min … max): 971.5 ms … 983.4 ms 10 runs
Benchmark 2: /Users/Knoble/code/git/git-status
Time (mean ± σ): 987.0 ms ± 6.0 ms [User: 419.5 ms, System: 461.5 ms]
Range (min … max): 980.5 ms … 1000.1 ms 10 runs
Benchmark 3: git status --ignore-submodules=all
Time (mean ± σ): 29.2 ms ± 0.5 ms [User: 8.5 ms, System: 19.1 ms]
Range (min … max): 27.8 ms … 30.4 ms 90 runs
Benchmark 4: ~/code/git/git-status --ignore-submodules=all
Time (mean ± σ): 32.3 ms ± 0.6 ms [User: 10.5 ms, System: 19.1 ms]
Range (min … max): 31.0 ms … 35.0 ms 81 runs
Summary
git status --ignore-submodules=all ran
1.11 ± 0.03 times faster than ~/code/git/git-status --ignore-submodules=all
33.47 ± 0.63 times faster than git status
33.78 ± 0.66 times faster than /Users/Knoble/code/git/git-status
Is there something I needed to enable to see the speedup (am I « holding it wrong »)? Or is this series not actually implementing the parallelization yet—perhaps it is a series of preparatory commits?
I look forward to an implementation of this feature; searching the mailing list reveals some candidates which don’t appear to have ever made it to master [2].
[1]: https://lore.kernel.org/git/CALnO6CCoXOZTsfag6yN_Ffn+H7KE-KTzm+P-GqLKnDMg8j_Qmg@xxxxxxxxxxxxxx/
[2]: https://lore.kernel.org/git/20220922232947.631309-1-calvinwan@xxxxxxxxxx/
