Re: [RFC PATCH 2/3] Make ce_compare_gitlink thread-safe

[Atneya Nair <atneya@google.com>]

On Tue, Mar 5, 2024 at 9:08 AM Junio C Hamano <gitster@pobox.com> wrote:
>
> Atneya Nair <atneya@google.com> writes:
>
> > To enable parallel update of the read cache for submodules,
> > ce_compare_gitlink must be thread safe (for different objects).
> >
> > Remove string interning in do_config_from (called from
> > repo_submodule_init) and add locking around accessing the ref_store_map.
>
> This step does two independent things, even though they may have
> dependencies, i.e., for one to be a solution for the problem it is
> tackling, the other may have to be there already.  E.g., even after
> calls to ce_compare_gitlink() get serialized via a mutex, it may for
> some reason not work without giving each kvi.filename its own copy
> [*], and if that is the case, you may need to have the "stop
> interning" step in a single patch with its own justification, and
> then "have mutex around ref_store calls" patch has to come after it.
>

What is the appropriate way to split an intermediate patch into two? Simply
adding the additional commit as 3 of 4 would cause a mismatch between patch-set
versions? Would that cause any issues?