Re: [PATCH v2 0/7] thread lazy_init_name_hash

> On Thu, Mar 23, 2017 at 8:46 PM,  <git@jeffhostetler.com> wrote:
>> This patch series is a performance optimization for
>> lazy_init_name_hash() in name-hash.c on very large
>> repositories.
>>
>> This change allows lazy_init_name_hash() to optionally
>> use multiple threads when building the the_index.dir_hash
>> and the_index.name_hash hashmaps.  The original code path
>> has been preserved and is used when the repo is small or
>> the system does not have sufficient CPUs.
>
> If sha1 verification in the index file can now be optionally skipped,
> I wonder if you would have faster startup time by storing hashes in
> the index as an extension. I have never tried it (though I planned to
> have some sort of caching for this) but I would guess loading hashes
> would cost less than 0.27 seconds, hopefully closer to 0.05 seconds.
>