From: Geert Jansen <gerardu@amazon.com>
Date: Thu, 08 Nov 2018 20:58:19 GMT
Subject: Re: [RFC PATCH] index-pack: improve performance on NFS
Message-ID: <20181108205819.GA93589@amazon.com>
In-Reply-To: <20181108120256.GA29432@sigill.intra.peff.net>

On Thu, Nov 08, 2018 at 07:02:57AM -0500, Jeff King wrote:

> Yes, testing and review. :)
> 
> I won't send the series out just yet, as I suspect it could use another
> read-through on my part. But if you want to peek at it or try some
> timings, it's available at:
> 
>   https://github.com/peff/git jk/loose-cache

I gave this branch a go. There's a performance regression as I'm getting a
clone speed of about 100 KiB/s while with the previous patch I got around 20
MiB/s. The culprint appears to be a very large number of stat() calls on
".git/objects/info/alternates". The call stack is:

 -> quick_has_loose()
 -> prepare_alt_odb()
 -> read_info_alternates()