From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Habouzit Subject: Re: q: faster way to integrate/merge lots of topic branches? Date: Wed, 23 Jul 2008 21:09:20 +0200 Message-ID: <20080723190920.GG20614@artemis.madism.org> References: <20080723130518.GA17462@elte.hu> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="0rSojgWGcpz+ezC3"; protocol="application/pgp-signature"; micalg=SHA1 Cc: Ingo Molnar , git@vger.kernel.org To: Linus Torvalds X-From: git-owner@vger.kernel.org Wed Jul 23 21:10:38 2008 Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1KLjjI-0000tJ-8n for gcvg-git-2@gmane.org; Wed, 23 Jul 2008 21:10:28 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753526AbYGWTJX (ORCPT ); Wed, 23 Jul 2008 15:09:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753353AbYGWTJX (ORCPT ); Wed, 23 Jul 2008 15:09:23 -0400 Received: from pan.madism.org ([88.191.52.104]:45695 "EHLO hermes.madism.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753262AbYGWTJW (ORCPT ); Wed, 23 Jul 2008 15:09:22 -0400 Received: from madism.org (def92-12-88-177-251-208.fbx.proxad.net [88.177.251.208]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "artemis.madism.org", Issuer "madism.org" (verified OK)) by hermes.madism.org (Postfix) with ESMTPS id 53E833A791; Wed, 23 Jul 2008 21:09:21 +0200 (CEST) Received: by madism.org (Postfix, from userid 1000) id 4ED50451BC8; Wed, 23 Jul 2008 21:09:20 +0200 (CEST) Mail-Followup-To: Pierre Habouzit , Linus Torvalds , Ingo Molnar , git@vger.kernel.org Content-Disposition: inline In-Reply-To: X-Face: $(^e[V4D-[`f2EmMGz@fgWK!e.B~2g.{08lKPU(nc1J~z\4B>*JEVq:E]7G-\6$Ycr4<;Z!|VY6Grt]+RsS$IMV)f>2)M="tY:ZPcU;&%it2D81X^kNya0=L]"vZmLP+UmKhgq+u*\.dJ8G!N&=EvlD User-Agent: Madmutt/devel (Linux) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: --0rSojgWGcpz+ezC3 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jul 23, 2008 at 05:59:01PM +0000, Linus Torvalds wrote: > In fact, the two top entries in a profile look roughly like: >=20 > 102161 70.2727 libz.so.1.2.3 libz.so.1.2.3 (no = symbols) > 7685 5.2862 git git find= _pack_entry_one > ... >=20 > ie 70% of the time is just purely unpacking the data, and another 5% is= =20 > just finding it. We could perhaps improve on it, but not a whole lot. Well there is an easy way though, that could reduce that: using adaptative compression. I proposed a patch once upon a time, that set the compression strengh to 0 for "small" objects with a configurable cut-off. If you do that, most trees, commits messages and so on aren't compressed, and it will reduce (with IIRC a 5-liner) this time quite dramatically. I could maybe resurect it to see if for people that do the kind of things Ingo does it helps. By setting the cut-off at 1k, I had packs being less than 1% bigger IIRC. I'll try to find it again and run your tests with it to see how much it helps. [ Of course, it doesn't invalidate the rest of your mail about being more clever with git-merge, but still, we could reduce this 70% of zlib time quite a lot with that ] --=20 =C2=B7O=C2=B7 Pierre Habouzit =C2=B7=C2=B7O madcoder@debia= n.org OOO http://www.madism.org --0rSojgWGcpz+ezC3 Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAkiHgeAACgkQvGr7W6Hudhy+6QCffTcbiOmR7F1BtfRrhCF3yYNN FPEAn0CP3F/AYOAfm1h6aIII+FDGxUwT =eNLb -----END PGP SIGNATURE----- --0rSojgWGcpz+ezC3--