From: Erik Faye-Lund <kusmabite@gmail.com>
Date: Wed, 12 Feb 2014 11:59:56 GMT
Subject: Re: Make the git codebase thread-safe
Message-ID: <CABPQNSZ_LLg5i+mpwUj7pzXVQMY1tcXz2gJ+PWG-mP1iyjxoaw@mail.gmail.com>
In-Reply-To: <CA+TurHgyUK5sfCKrK+3xY8AeOg0t66vEvFxX=JiA9wXww7eZXQ@mail.gmail.com>

On Wed, Feb 12, 2014 at 2:54 AM, Stefan Zager <szager@chromium.org> wrote:
> We in the chromium project have a keen interest in adding threading to
> git in the pursuit of performance for lengthy operations (checkout,
> status, blame, ...).  Our motivation comes from hitting some
> performance walls when working with repositories the size of chromium
> and blink:
>
> https://chromium.googlesource.com/chromium/src
> https://chromium.googlesource.com/chromium/blink
>
> We are particularly concerned with the performance of msysgit, and we
> have already chalked up a significant performance gain by turning on
> the threading code in pack-objects (which was already enabled for
> posix platforms, but not on msysgit, owing to the lack of a correct
> pread implementation).

How did you manage to do this? I'm not aware of any way to implement
pread on Windows (without going down the insanity-path of wrapping and
potentially locking inside every IO operation)...