From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Miles Bader Newsgroups: gmane.emacs.devel Subject: Re: MAINTAINERS file Date: Fri, 07 Mar 2008 12:09:24 +0900 Message-ID: References: <18375.18663.981150.252393@kahikatea.snap.net.nz> <87od9wt19m.fsf@elegiac.orebokech.com> <87tzjnvjhc.fsf@red-bean.com> <87ablffdf7.fsf@catnip.gol.com> <4s4pbm9lrb.fsf@fencepost.gnu.org> <87skz4n6lu.fsf@catnip.gol.com> <87r6enpy30.fsf@catnip.gol.com> <47D050B0.1060608@emf.net> <87fxv3pf6o.fsf@catnip.gol.com> <47D0C01F.60100@emf.net> Reply-To: Miles Bader NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1204859420 22724 80.91.229.12 (7 Mar 2008 03:10:20 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 7 Mar 2008 03:10:20 +0000 (UTC) Cc: Glenn Morris , rms@gnu.org, lekktu@gmail.com, emacs-devel@gnu.org, kfogel@red-bean.com, Stefan Monnier , paul.r.ml@gmail.com To: Thomas Lord Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Mar 07 04:10:46 2008 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1JXSyp-0005Hd-Dj for ged-emacs-devel@m.gmane.org; Fri, 07 Mar 2008 04:10:43 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JXSyH-00038r-M3 for ged-emacs-devel@m.gmane.org; Thu, 06 Mar 2008 22:10:09 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1JXSyE-00038m-6b for emacs-devel@gnu.org; Thu, 06 Mar 2008 22:10:06 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1JXSyC-00038H-Ln for emacs-devel@gnu.org; Thu, 06 Mar 2008 22:10:05 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1JXSyC-00038A-JG for emacs-devel@gnu.org; Thu, 06 Mar 2008 22:10:04 -0500 Original-Received: from tyo201.gate.nec.co.jp ([202.32.8.193]) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1JXSy1-0004Uy-OL; Thu, 06 Mar 2008 22:09:54 -0500 Original-Received: from relay11.aps.necel.com ([10.29.19.46]) by tyo201.gate.nec.co.jp (8.13.8/8.13.4) with ESMTP id m2739Psk023018; Fri, 7 Mar 2008 12:09:25 +0900 (JST) Original-Received: from relay21.aps.necel.com ([10.29.19.20] [10.29.19.20]) by relay11.aps.necel.com with ESMTP; Fri, 7 Mar 2008 12:09:25 +0900 Original-Received: from dhapc248.dev.necel.com ([10.114.112.215] [10.114.112.215]) by relay21.aps.necel.com with ESMTP; Fri, 7 Mar 2008 12:09:25 +0900 Original-Received: by dhapc248.dev.necel.com (Postfix, from userid 31295) id 055DE5E9; Fri, 7 Mar 2008 12:09:25 +0900 (JST) System-Type: i686-pc-linux-gnu Blat: Foop In-Reply-To: <47D0C01F.60100@emf.net> (Thomas Lord's message of "Thu, 06 Mar 2008 20:10:07 -0800") Original-Lines: 65 X-detected-kernel: by monty-python.gnu.org: Solaris 8 (1) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:91579 Archived-At: Thomas Lord writes: >> Geez, don't be silly Tom. The problem is that the arch implementation >> plays bugger-all attention to efficiency, > > That's nonsense and (unintentionally, I assume) insulting. > > It pays quite a bit of attention to performance. No insult was intended. I like arch, I think it was a great design (I still use tla daily!), and I have great respect for you. However, in practice, tla often feels more like a proof-of-concept than something which has had real attention paid to performance and optimization. Git development _has_ paid real attention to performance, and it really shows. [I'm not attempting to distinguish between inherent slowness (where speed is hobbled by the underlying design) and lack of optimization, merely observing that in practice, tla is slow. No doubt there are elements of both involved.] > There is some old mailing list message from Linus, around the > time git was launched, that drives most of that. His very narrow > aim (in the area it differs from Arch) was to make "commit" > times as quick as possible. That was, more or less, his specific > excuse for not using arch rather than writing git. > > Commit times are a strange metric to optimize for in a changeset-oriented > system. There are plenty of other design goals and constraints to > consider. > > Why not look at check-out times or file retrieval times? > In many situations, for Arch, those are between O(1) > and O(n) where n is the number of bytes in the revision? I'm not talking about commit times. I'm talking about basically _every_ operation which I do on a regular basic (e.g. update working dir, merge other branch, do file/tree diff, commit) . Git is really, _really_ fast. Scary fast. Tla is almost always palpably "slow", even when the repository is on local disk and the revision library has every applicable revision. I still use, of course, so obviously it's in the realm of "acceptable", but I've become accustomed to waiting. > Or, if you really want git-speed (or better) commit times > for arch -- that can be done with some *modest* coding > by "committing to the revision library" and computing > the changeset more lazily. I'm sure there are many things that could be done to optimize tla and speed things up. Indeed, mostly what I'm trying to say is that by-and-large, that work _hasn't been done_ on tla, and it _has_ been done on git, and this fact is very obvious when using these systems. In part this is a historical accident -- git happened to come of age in a community where there are lots and lots of performance-obsessed people well acquainted with the things you need to do to really make things fast (and of course it's no accident that it's _fastest_ on a system with a linux kernel...), and willing to put in the effort to make it so. -Miles -- Any man who is a triangle, has thee right, when in Cartesian Space, to have angles, which when summed, come to know more, nor no less, than nine score degrees, should he so wish. [TEMPLE OV THEE LEMUR]