Re: [PATCH 1/5] t5309: run expected-to-fail `index-pack`s with `--threads=1`

[Taylor Blau <me@ttaylorr.com>]

On Wed, Jan 10, 2024 at 02:18:52PM -0800, Junio C Hamano wrote:
> Taylor Blau <me@ttaylorr.com> writes:
>
> > But that requires us to tweak production code (albeit at a negligible
> > cost) in order to appease LSan in this narrow circumstance. Another
> > approach is to simply run these expected-to-fail `index-pack`
> > invocations with `--threads=1` so that we bypass the above issue
> > entirely.
>
> But of course, multi-threaded operation that production folks use
> will not be tested at all with the alternative.

Just the ones that we expect to fail *and* are in test scripts which are
marked as leak-free.

> > The downside of that approach is that the test doesn't match our
> > production code as well as it did before (where we might have run those
> > same `index-pack` invocations with >1 thread, depending on how many CPUs
> > the testing machine has). The risk there is that we might miss a
> > regression that would leave us in an inconsistent state. But that feels
> > rather unlikely in practice, and there are many other tests related to
> > `index-pack` in the suite.
>
> As long as "make sure we spawn all of them atmically" has negligible
> downside, I'd rather take that approach. Buying predictability with
> minimum cost is quite attractive.

Like I said earlier, I have no strong preference between either
approach. If you want to pick up Peff's patch instead of these five,
that is fine with me :-).

Thanks,
Taylor