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Date:   Wed, 20 Sep 2017 14:57:25 -0400
From:   Jeff King <peff@peff.net>
To:     Michael Haggerty <mhagger@alum.mit.edu>
Cc:     Junio C Hamano <gitster@pobox.com>,
        Stefan Beller <sbeller@google.com>,
        Johannes Schindelin <Johannes.Schindelin@gmx.de>,
        =?utf-8?B?Tmd1eeG7hW4gVGjDoWkgTmfhu41j?= Duy <pclouds@gmail.com>,
        =?utf-8?B?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason <avarab@gmail.com>,
        Brandon Williams <bmwill@google.com>, git@vger.kernel.org
Subject: Re: [PATCH v2 00/21] Read `packed-refs` using mmap()
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References: <cover.1505799700.git.mhagger@alum.mit.edu>
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On Tue, Sep 19, 2017 at 08:22:08AM +0200, Michael Haggerty wrote:

> This branch is also available from my fork on GitHub as branch
> `mmap-packed-refs`.
> 
> My main uncertainties are:
> 
> 1. Does this code actually work on Windows?
> 
> 2. Did I implement the new compile-time option correctly? (I just
>    cargo-culted some existing options.) Is there some existing option
>    that I could piggy-back off of instead of adding a new one?
> 
> 3. Is a compile-time option sufficient, or would the `mmap()` option
>    need to be configurable at runtime, or even tested at repository
>    create time as is done for some other filesystem properties in
>    `create_default_files()`?

I can't really answer (1) due to lack of knowledge. For (2), I think
it's mostly good, though I raised a small nit. For (3), I think this is
really an OS restriction and not a filesystem one, so probably
build-time is OK (though of course Windows people may be able to correct
me).

I left a few comments, but overall it looks quite good to me.

-Peff