Subject: Re: [PATCH v5 5/6] p5310-pack-bitmaps.sh: enable `pack.writeReverseIndex`

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Tue, 26 Jul 2022 15:54:04 +0200

On Tue, Jul 26 2022, Derrick Stolee wrote:

> On 7/26/2022 3:15 AM, Ævar Arnfjörð Bjarmason wrote:
>> Rather than comparing HEAD to your current tree it's generally better
>> to do something like:
>> 
>> 	GIT_PERF_MAKE_OPTS='-j3' ./run HEAD~ HEAD [...]
>
> Using the 'run' script fixes the perf test in the worktree and tests
> different versions of the 'git' executable.
>
> That doesn't work when the change is in the performance test itself.

Thanks, I'm clearly wrong about that. I didn't look enough at the
context.

But then we're losing the perf test coverage for the case where we don't
have the *.rev files. Isn't it better to run both with & without *.rev,
perhaps by splitting up the test file? We could make it a function in
perf/lib-bitmap.sh that we call both with & without the wanted *.rev
repack config.

I suspect that's also subtly broken, in that t/perf assumes that it can
re-use the repo for a given <rev>, but this is modifying that repo, so
if you run e.g. test Y after this Y, that Y will unexpectedly get a
repack'd repo ...

But we could just start the test with a git clone . "$TEST_NAME" or
whatever, then repack that with whatever options we want...