From: Thomas Rast <trast@inf.ethz.ch>
Date: Thu, 30 May 2013 16:44:35 GMT
Subject: Re: Poor performance of git describe in big repos
Message-ID: <87bo7sbeoc.fsf@linux-k42r.v.cablecom.net>
In-Reply-To: <87ip20bfq4.fsf@linux-k42r.v.cablecom.net>

Thomas Rast <trast@inf.ethz.ch> writes:

> I had a brief look around sha1_file.c, in particular sha1_object_info,
> and it turns out we lack the "deflate only early part" logic as I
> suspected.  So that'll have to be fixed first.  After that I *think* it
> should automatically carry over into the tag readers.

Strike that, I'm wrong.  sha1_object_info is fast even for these big
loose objects.

The culprit, according to some callgrind investigation, is
lookup_commit_reference_gently() [for the unannotated case] or
deref_tag() [annotated case] calling parse_object().

-- 
Thomas Rast
trast@{inf,student}.ethz.ch