Re: [PATCH] fast-export: ensure we traverse commits in topological order

From: Jeff King <peff@peff.net>
Date: Feb 11, 2009, 17:53 UTC
Message-ID: <20090211175354.GB19749@coredump.intra.peff.net>
In-Reply-To: <51419b2c0902110723y75d0c4a4r34cf92cf371313ea@mail.gmail.com>

On Wed, Feb 11, 2009 at 08:23:22AM -0700, Elijah Newren wrote:

> I'm a little surprised why my numbers were so much lower than yours,
> though.  I don't think of my hard drive and CPU as being all that
> quick -- is this a difference in packing, by chance, with your
> repository not having recently been repacked?

I don't think the hard drive matters much at all; the CPU is pegged the whole time. I'm not fully packed, but almost so. I suspect it is a combination of:

  1. I compile git with "-g" and no optimizations to make debugging
     easier.

  2. My system sucks. It is a 1.8GHz dual Athlon from around 2003.
     fast-export should be pretty memory intensive, which I'm sure is
     saturating my totally rocking 266MHz FSB.

Just for fun, I tried:

  - fully repacking; no change

  - compiling with -O2; shaved off about 2s. Not too surprising;
    previous profiling has shown that git spends a lot of time in zlib,
    and I am dynamically linking against an optimized version.

So I think it is mainly (2) above, assuming your machine sucks a lot less than mine.

-Peff