On 4/1/21 11:40 AM, Jeff Hostetler via GitGitGadget wrote:
> This patch series adds a builtin FSMonitor daemon to Git.
>
> This daemon uses platform-specific filesystem notifications to keep track of
> changes to a working directory. It also listens over the "Simple IPC"
> facility for client requests and responds with a list of files/directories
> that have been recently modified.
...
> This RFC version includes support for Windows and MacOS file system events.
> A Linux version will be submitted in a later patch series.
Similarly to my message about testing the Windows performance, I
repeated those tests on macOS.
The same testing procedure was used, except now I'm on a MacBook
Pro laptop instead of a desktop, so the CPU power is likely to be
significantly less.
However, I am pleased to report that the FS Monitor feature is
a clear winner in all scenarios. Using the untracked cache is
still highly recommended, but not necessary in order to get a
speed boost from the builtin FS Montiro.
Sparse Index Disabled, Untracked Cache Enabled
----------------------------------------------
Benchmark #1: none (clean)
Time (mean ± σ): 3.980 s ± 0.026 s [User: 919.1 ms, System: 1891.8 ms]
Range (min … max): 3.940 s … 4.028 s 10 runs
Benchmark #2: builtin (clean)
Time (mean ± σ): 477.9 ms ± 6.6 ms [User: 772.9 ms, System: 379.7 ms]
Range (min … max): 468.1 ms … 489.5 ms 10 runs
Summary
'builtin (clean)' ran
8.33 ± 0.13 times faster than 'none (clean)'
Benchmark #1: none (dirty)
Time (mean ± σ): 5.411 s ± 0.199 s [User: 2.993 s, System: 4.120 s]
Range (min … max): 5.026 s … 5.756 s 10 runs
Benchmark #2: builtin (dirty)
Time (mean ± σ): 2.588 s ± 0.025 s [User: 3.752 s, System: 2.853 s]
Range (min … max): 2.540 s … 2.628 s 10 runs
Summary
'builtin (dirty)' ran
2.09 ± 0.08 times faster than 'none (dirty)'
Sparse Index Disabled, Untracked Cache Disabled
-----------------------------------------------
Benchmark #1: none (clean)
Time (mean ± σ): 2.993 s ± 0.115 s [User: 1.562 s, System: 2.289 s]
Range (min … max): 2.741 s … 3.167 s 10 runs
Benchmark #2: builtin (clean)
Time (mean ± σ): 939.4 ms ± 10.1 ms [User: 1.452 s, System: 1.519 s]
Range (min … max): 925.1 ms … 961.0 ms 10 runs
Summary
'builtin (clean)' ran
3.19 ± 0.13 times faster than 'none (clean)'
Benchmark #1: none (dirty)
Time (mean ± σ): 8.245 s ± 1.118 s [User: 3.204 s, System: 5.684 s]
Range (min … max): 5.927 s … 8.985 s 10 runs
Benchmark #2: builtin (dirty)
Time (mean ± σ): 2.969 s ± 0.034 s [User: 3.832 s, System: 3.160 s]
Range (min … max): 2.927 s … 3.023 s 10 runs
Summary
'builtin (dirty)' ran
2.78 ± 0.38 times faster than 'none (dirty)'
Sparse Index Enabled, Untracked Cache Enabled
---------------------------------------------
Benchmark #1: none (clean)
Time (mean ± σ): 1.250 s ± 0.050 s [User: 216.9 ms, System: 1836.9 ms]
Range (min … max): 1.177 s … 1.300 s 10 runs
Benchmark #2: builtin (clean)
Time (mean ± σ): 89.3 ms ± 2.9 ms [User: 51.3 ms, System: 22.6 ms]
Range (min … max): 81.9 ms … 93.5 ms 31 runs
Summary
'builtin (clean)' ran
14.01 ± 0.72 times faster than 'none (clean)'
Benchmark #1: none (dirty)
Time (mean ± σ): 2.087 s ± 0.095 s [User: 320.9 ms, System: 3327.5 ms]
Range (min … max): 1.943 s … 2.242 s 10 runs
Benchmark #2: builtin (dirty)
Time (mean ± σ): 233.5 ms ± 2.7 ms [User: 165.5 ms, System: 74.1 ms]
Range (min … max): 227.8 ms … 237.1 ms 12 runs
Summary
'builtin (dirty)' ran
8.94 ± 0.42 times faster than 'none (dirty)'
Sparse Index Enabled, Untracked Cache Disabled
----------------------------------------------
Benchmark #1: none (clean)
Time (mean ± σ): 1.277 s ± 0.101 s [User: 215.5 ms, System: 1877.9 ms]
Range (min … max): 1.138 s … 1.458 s 10 runs
Benchmark #2: builtin (clean)
Time (mean ± σ): 300.0 ms ± 6.1 ms [User: 119.4 ms, System: 183.1 ms]
Range (min … max): 293.0 ms … 313.2 ms 10 runs
Summary
'builtin (clean)' ran
4.26 ± 0.35 times faster than 'none (clean)'
Benchmark #1: none (dirty)
Time (mean ± σ): 2.488 s ± 0.088 s [User: 432.6 ms, System: 3631.6 ms]
Range (min … max): 2.328 s … 2.601 s 10 runs
Benchmark #2: builtin (dirty)
Time (mean ± σ): 636.4 ms ± 12.8 ms [User: 266.2 ms, System: 374.0 ms]
Range (min … max): 624.4 ms … 671.0 ms 10 runs
Summary
'builtin (dirty)' ran
3.91 ± 0.16 times faster than 'none (dirty)'
Here are my results for the Git repository:
Untracked Cache Enabled
-----------------------
Benchmark #1: none (clean)
Time (mean ± σ): 51.2 ms ± 4.0 ms [User: 12.9 ms, System: 61.2 ms]
Range (min … max): 46.2 ms … 65.7 ms 54 runs
Benchmark #2: builtin (clean)
Time (mean ± σ): 38.6 ms ± 1.7 ms [User: 9.9 ms, System: 9.7 ms]
Range (min … max): 28.6 ms … 42.4 ms 75 runs
Summary
'builtin (clean)' ran
1.33 ± 0.12 times faster than 'none (clean)'
Benchmark #1: none (dirty)
Time (mean ± σ): 108.1 ms ± 7.2 ms [User: 27.2 ms, System: 126.9 ms]
Range (min … max): 97.6 ms … 130.4 ms 25 runs
Benchmark #2: builtin (dirty)
Time (mean ± σ): 91.7 ms ± 3.8 ms [User: 25.4 ms, System: 27.0 ms]
Range (min … max): 88.5 ms … 105.1 ms 32 runs
Summary
'builtin (dirty)' ran
1.18 ± 0.09 times faster than 'none (dirty)'
Untracked Cache Disabled
------------------------
Benchmark #1: none (clean)
Time (mean ± σ): 59.5 ms ± 4.0 ms [User: 15.2 ms, System: 67.7 ms]
Range (min … max): 55.5 ms … 71.6 ms 46 runs
Benchmark #2: builtin (clean)
Time (mean ± σ): 48.9 ms ± 1.0 ms [User: 12.5 ms, System: 17.3 ms]
Range (min … max): 46.7 ms … 51.3 ms 58 runs
Summary
'builtin (clean)' ran
1.22 ± 0.08 times faster than 'none (clean)'
Benchmark #1: none (dirty)
Time (mean ± σ): 124.4 ms ± 6.8 ms [User: 31.5 ms, System: 140.2 ms]
Range (min … max): 116.8 ms … 140.0 ms 24 runs
Benchmark #2: builtin (dirty)
Time (mean ± σ): 104.1 ms ± 1.7 ms [User: 27.4 ms, System: 37.8 ms]
Range (min … max): 99.7 ms … 106.6 ms 27 runs
Summary
'builtin (dirty)' ran
1.19 ± 0.07 times faster than 'none (dirty)'
I think it valuable to point out that in my initial tests I had forgotten
to disable the Watchman-based FS Monitor hook, and the results looked even
more impressive (on the small Git repository). Dropping the hook overhead is
a huge benefit here.
Thanks,
-Stolee
