From: Jeff King <peff@peff.net>
To: Michael Haggerty <mhagger@alum.mit.edu>
Cc: Martin Fick <mfick@codeaurora.org>,
git discussion list <git@vger.kernel.org>,
Junio C Hamano <gitster@pobox.com>
Subject: Re: remove_duplicates() in builtin/fetch-pack.c is O(N^2)
Date: Tue, 22 May 2012 03:37:40 -0400 [thread overview]
Message-ID: <20120522073740.GA10093@sigill.intra.peff.net> (raw)
In-Reply-To: <4FBB3D2B.4010300@alum.mit.edu>
On Tue, May 22, 2012 at 09:15:55AM +0200, Michael Haggerty wrote:
> If it is not too much trouble, please let me know where I can obtain
> your test repo and what commands you used to get your result. (Was
> the local repo already a full clone of the remote, including all 400k
> references? How was the remote set up--sharing data or not, local or
> remote? Warm or cold disk cache?)
I've put the repo up at:
https://gist.github.com/raw/2767328/603926240fabb4d3e3abc3c93a1913d91852cc7e/rails.tar.gz
You can reproduce the slow-down with:
cd rails.git &&
git fetch . refs/*:refs/*
which should be a no-op, as we already have all of the refs. I don't
know if the problem is actually specific to fetch; that was just how I
noticed it.
When I try it with both 'next' and v1.7.10, I see that the latter is
much faster. I did my tests with a warm cache, but the interesting
number is the CPU time, which is quite different.
-Peff
next prev parent reply other threads:[~2012-05-22 7:38 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-21 8:13 remove_duplicates() in builtin/fetch-pack.c is O(N^2) Michael Haggerty
2012-05-21 9:09 ` Junio C Hamano
2012-05-21 9:42 ` demerphq
2012-05-21 17:45 ` Jeff King
2012-05-21 22:14 ` Jeff King
2012-05-21 22:17 ` [PATCH 1/5] fetch-pack: sort incoming heads Jeff King
2012-05-22 20:08 ` Junio C Hamano
2012-05-22 20:23 ` Jeff King
2012-05-24 6:04 ` Jeff King
2012-05-21 22:17 ` [PATCH 2/5] fetch-pack: avoid quadratic behavior in remove_duplicates Jeff King
2012-05-21 22:19 ` [PATCH 3/5] add sorting infrastructure for list refs Jeff King
2012-05-21 22:19 ` [PATCH 4/5] fetch-pack: sort the list of incoming refs Jeff King
2012-05-21 22:23 ` [PATCH 5/5] fetch-pack: avoid quadratic loop in filter_refs Jeff King
2012-05-22 20:16 ` Junio C Hamano
2012-05-21 23:52 ` remove_duplicates() in builtin/fetch-pack.c is O(N^2) Jeff King
2012-05-22 0:07 ` Jeff King
2012-05-22 3:59 ` Michael Haggerty
2012-05-22 4:11 ` Jeff King
2012-05-22 7:15 ` Michael Haggerty
2012-05-22 7:37 ` Jeff King [this message]
2012-05-22 13:28 ` Michael Haggerty
2012-05-22 17:33 ` Jeff King
2012-05-24 12:05 ` Michael Haggerty
2012-05-25 0:17 ` Martin Fick
2012-05-25 0:39 ` Jeff King
2012-05-25 0:54 ` Martin Fick
2012-05-25 1:04 ` Jeff King
2012-05-25 1:32 ` Martin Fick
2012-05-25 6:50 ` Jeff King
2012-05-22 12:18 ` Nguyen Thai Ngoc Duy
2012-05-22 13:35 ` Michael Haggerty
2012-05-22 17:01 ` Jeff King
2012-05-22 17:35 ` Junio C Hamano
2012-05-22 17:46 ` Jeff King
2012-05-24 4:54 ` Michael Haggerty
2012-05-23 1:20 ` Nguyen Thai Ngoc Duy
2012-05-22 16:16 ` Junio C Hamano
2012-05-21 18:15 ` Martin Fick
2012-05-21 19:41 ` Jeff King
2012-05-21 22:08 ` Junio C Hamano
2012-05-21 22:24 ` Jeff King
2012-05-22 5:51 ` Martin Fick
2012-05-22 18:21 ` Jeff King
2012-05-22 22:19 ` Martin Fick
2012-05-22 23:23 ` Junio C Hamano
2012-05-23 0:46 ` Martin Fick
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