Re: [PATCH] commit-graph: disable GIT_COMMIT_GRAPH_PARANOIA by default

From: Junio C Hamano <gitster@pobox.com>
Date: Nov 15, 2023, 00:44 UTC
Message-ID: <xmqq4jhnyhe1.fsf@gitster.g>
In-Reply-To: <20231114194310.GC2092538@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 15 quoted lines

> What I'm getting as it that I think we have three options for v2.43:
>
>   1. Ship what has been in the release candidates, which has a known
>      performance regression (though the severity is up for debate).
>
>   2. Flip the default to "0" (i.e., Patrick's patch in this thread). We
>      know that loosens some cases versus 2.42, which may be considered a
>      regression.
>
>   3. Sort it out before the release. We're getting pretty close to do
>      a lot new work there, but I think the changes should be small-ish.
>      The nuclear option is ejecting the topic and re-doing it in the
>      next cycle.
>
> I don't have a really strong preference between the three.

I've been (naively) assuming that #1 is everybody's preference, simply because #2 does introduce a regression in the correctness department (as opposed to a possible performance regression caused by #1), and because #3 has a high risk of screwing up.

As long as the performance regression is known and on our radar, I'd say that working on a maintenance release after Thanksgiving would be sufficient.

I might be underestimating the impact of the loss of performance, though, in which case I'd consider that nuclear one, which is the simplest and least risky.

Thanks.