From: Junio C Hamano <gitster@pobox.com>
Date: Mon, 19 Aug 2019 17:36:25 GMT
Subject: Re: [PATCH v2 0/1] pack-refs: always refreshing after take the lock file
Message-ID: <xmqqr25hxdk6.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20190816204906.GA29853@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

> I'm undecided on this. I think reftables are still a while off, and even
> once they are here, many people will still be using the older format. So
> it makes sense to still apply fixes to the old code.

Yeah.

> What I wonder, though, is whether always refreshing will cause a
> noticeable performance impact (and that's why I was so slow in
> responding -- I had hoped to try to come up with some numbers, but I
> just hadn't gotten around to it).
>
> My gut says it's _probably_ not an issue, but it would be nice to have
> some data to back it up.

I am tempted to let correctness (and ease-of-reasoning about the
code) take precedence over potential and unknown performance issue,
at least for now.  A single liner is rather simple to revert (or in
the worst case we could add "allow pack-refs to efficiently lose a
ref to a race" configuration option) anyway.