From: Junio C Hamano <gitster@pobox.com>
Date: Mon, 05 Dec 2011 17:38:22 GMT
Subject: Re: Debugging git-commit slowness on a large repo
Message-ID: <7vr50inckx.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20111203002347.GB2950@centaur.lab.cmartin.tk>

Carlos Martín Nieto <cmn@elego.de> writes:

> ... At one
> point, commit forgot how to write the tree cache to the index (a
> performance optimisation). Do the times improve if you run 'git
> read-tree HEAD' between one commit and another? Note that this will
> reset the index to the last commit, though for the tests I image you
> use some variation of 'git commit -a'.
>
> Thomas Rast wrote a patch to re-teach commit to store the tree cache,
> but there were some issues and never got applied.

Ahh, I forgot all about that exchange.

  http://thread.gmane.org/gmane.comp.version-control.git/178480/focus=178515

The cache-tree mechanism has traditionally been one of the more important
optimizations and it would be very nice if we can resurrect the behaviour
for "git commit" too.