From: Derrick Stolee <stolee@gmail.com>
Date: Fri, 27 Dec 2019 14:53:23 GMT
Subject: Re: [PATCH 3/3] commit-graph: stop using full rev_info for diffs
Message-ID: <061c6800-1516-ddd9-968d-a1274e93d6a1@gmail.com>
In-Reply-To: <20191222093222.GC3460818@coredump.intra.peff.net>

On 12/22/2019 4:32 AM, Jeff King wrote:
> When we perform a diff to get the set of changed paths for a commit,
> we initialize a full "struct rev_info" with setup_revisions(). But the
> only part of it we use is the diff_options struct. Besides being overly
> complex, this also leaks memory, as we use the fake argv to
> setup_revisions() create a pending array which is never cleared.
> 
> Let's just use diff_options directly. This reduces the peak heap usage
> of "git commit-graph write --changed-paths" on linux.git from ~4GB to
> ~1.2GB.

In my testing, this went from ~6gb to ~4gb.

I'm guessing that my memory difference is related to how poorly my
packs are repacked/redeltified.

Thanks,
-Stolee