Re: [GSoC] Git Blog 11

Christian Couder [off-list ref] 于2021年8月2日周一 下午2:25写道：

On Sun, Aug 1, 2021 at 8:45 AM ZheNing Hu [off-list ref] wrote:

quoted

in some cases, this is the result of the performance test of
`t/perf/p1006-cat-file.sh`:

Test                                        HEAD~             HEAD
------------------------------------------------------------------------------------
1006.2: cat-file --batch-check              0.10(0.09+0.00)
0.11(0.10+0.00) +10.0%
1006.3: cat-file --batch-check with atoms   0.09(0.08+0.01)
0.09(0.06+0.03) +0.0%
1006.4: cat-file --batch                    0.62(0.58+0.04)
0.57(0.54+0.03) -8.1%
1006.5: cat-file --batch with atoms         0.63(0.60+0.02)
0.52(0.49+0.02) -17.5%

We can see that the performance of `git cat-file --batch` has been a
certain improvement!

Yeah, sure -8.1% or -17.5% is really nice! But why +10.0% for
`cat-file --batch-check`?

I think it's not very important. Because our optimization is skipping
parse_object_buffer(), git cat-file --batch-check will not set oi->contentp
by default, parse_object_buffer() will not be executed, Therefore, we did
not optimize `git cat-file --batch-check` at all. 10% may be small enough
for git cat-file --batch-check. The noise of environment even will cover it...

quoted

Tell a joke: removing 1984531500 if checking can reduce the startup
time of GTA5 by 70%. :-D

s/if checking/checks/

As this joke refers to:

https://rockstarintel.com/a-fan-reduces-gta-online-loading-times-by-70

it might be nice to add a link to help people like me who didn't know
about this and had to google it.

Ehhh, makes sense.

quoted

Currently the patch has not been submitted to the mailing list, let us
wait a bit...

Looking forward to it...

I am afraid we need to wait until ref-filter-raw-data merged into master.

The preview version is here:
https://github.com/adlternative/git/commit/6fcf51c4b1cbb510dac775a6fbf3db361bc1c327

Thanks.
--
ZheNing Hu