Re: [PATCH] xdiff: disable cleanup_records heuristic with --minimal

From: Niels Glodny <n.glodny@campus.lmu.de>
Date: Apr 27, 2025, 21:44 UTC
Message-ID: <f3140b32-5a25-448b-a99c-1604f6237cb8@campus.lmu.de>
In-Reply-To: <23078e29-8f1f-4eb3-be71-7ef419252bab@gmail.com>

Hi Phillip,

thank you for your detailed comments.

> Have you got any numbers for the performance change?

I have been using "git log -p -3000 --minimal > /dev/null", as in p4000-diff-algorithms.sh. With this patch, I get

  Time (mean ± σ):      2.363 s ±  0.023 s (25 runs)

Without this patch, I get

  Time (mean ± σ):      2.362 s ±  0.035 s  (25 runs)

So the difference is well within the margin of error. It doesn't look like it has any measurable impact on performance.

> I think the premise of this patch is sound, I've left a couple of comments below as I think we can simplify the code changes.

Thanks a lot! I'll apply your suggestions and send a revised version shortly.

Regards,

Niels