From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: git@vger.kernel.org, "Shawn O. Pearce" <spearce@spearce.org>
Subject: Re: [PATCH 2/2] pack-objects: optimize "recency order"
Date: Thu, 27 Oct 2011 23:01:50 +0200 [thread overview]
Message-ID: <CACBZZX6Ss4jLtdrDhLUNKCUjEHjHHKzfv-LMkOyTPDhRUXm4sQ@mail.gmail.com> (raw)
In-Reply-To: <1310084657-16790-3-git-send-email-gitster@pobox.com>
On Fri, Jul 8, 2011 at 02:24, Junio C Hamano <gitster@pobox.com> wrote:
> - Commits at the tip of tags are written together, in the hope that
> revision traversal done in incremental fetch (which starts by
> putting them in a revision queue marked as UNINTERESTING) will see a
> better locality of these objects;
We recently upgraded to 1.7.7 and I've traced a very large slowdown in
packing down to this commit.
On our repository packing used to take around 30 seconds, it now takes
about 4 minutes. Which means that cloning the repository went from
being slightly slow to pretty intolerable.
I haven't dug into why this is but I'm pretty sure it's because this
patch makes Git behave pathologically on repositories with a large
amount of tags. git.git itself has ~27k revs / and ~450 tags, or a tag
every ~60 revisions.
Try it on e.g. a repository with a couple of hundred thousand revs and
a tag every 10-20 revisions.
next prev parent reply other threads:[~2011-10-27 21:02 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-08 0:24 [PATCH 0/2] For improved pack locality Junio C Hamano
2011-07-08 0:24 ` [PATCH 1/2] core: log offset pack data accesses happened Junio C Hamano
2011-07-08 0:24 ` [PATCH 2/2] pack-objects: optimize "recency order" Junio C Hamano
2011-07-08 2:08 ` Shawn Pearce
2011-07-08 17:45 ` Junio C Hamano
2011-07-11 22:49 ` Nicolas Pitre
2011-07-08 22:47 ` Junio C Hamano
2011-07-09 0:42 ` Shawn Pearce
2011-10-27 21:01 ` Ævar Arnfjörð Bjarmason [this message]
2011-10-27 21:49 ` Ævar Arnfjörð Bjarmason
2011-10-27 22:02 ` Ævar Arnfjörð Bjarmason
2011-10-27 22:32 ` Jakub Narebski
2011-10-27 22:05 ` Junio C Hamano
2011-10-28 9:17 ` Ævar Arnfjörð Bjarmason
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