From: Duy Nguyen <pclouds@gmail.com>
Date: Thu, 06 Apr 2017 02:22:29 GMT
Subject: Re: [PATCH v2 0/7] thread lazy_init_name_hash
Message-ID: <CACsJy8CCb+i3xjtEY=6_dWCGw8VJHT1Mo5973YmQ-6xpTd=z=g@mail.gmail.com>
In-Reply-To: <1490276825-41544-1-git-send-email-git@jeffhostetler.com>

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.
-- 
Duy