Subject: Re: [PATCH v2 0/2] pack-bitmap: boundary-based bitmap traversal

From: Derrick Stolee <[email-masked]>
Date: Fri, 5 May 2023 13:59:31 -0400

On 5/5/2023 1:27 PM, Taylor Blau wrote:
> Here is a reroll of my series to implement a boundary-based bitmap
> traversal algorithm that I worked on towards the end of 2021 with Peff.
> 
> The algorithm is unchanged from the last version, but the implementation
> has been made much more straightforward, thanks to a very helpful
> suggestion from Stolee.
> 
> Instead of hackily trying to write down all of the UNINTERESTING commits
> between the tips and boundary within limit_list(), we can just perform a
> commit-only walk, which will give us the set of commits that we need.

Something that didn't seem to get attention in this version was buried
deep in the commentary of my high-level review [1]:

> For these reasons, I'm surprised that this patch completely replaces
> the old algorithm for the new one. I would prefer to see a config
> option that enables this new algorithm. It would be safer to deploy
> that way, too.

I still think it would be nice to keep the two algorithms for at least
a little while instead of completely removing the old one. Let's gather
some more evidence and get more reps in with the new algorithm before
making it the new default. I could imagine a scenario where someone
really wants to spend the extra time to make sure none of the objects
reachable from the UNINTERESTING commits are included in the output of
this diff.

[1] https://lore.kernel.org/git/[email-masked]/

Thanks,
-Stolee