From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff King Subject: Re: [PATCH 0/2] performance regression in mark_edges_uninteresting Date: Mon, 20 Jan 2014 17:29:36 -0500 Message-ID: <20140120222936.GA25291@sigill.intra.peff.net> References: <20140120212845.GA11451@sigill.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: git@vger.kernel.org To: =?utf-8?B?Tmd1eeG7hW4gVGjDoWkgTmfhu41j?= Duy X-From: git-owner@vger.kernel.org Mon Jan 20 23:29:43 2014 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1W5NLi-0000Fa-Ja for gcvg-git-2@plane.gmane.org; Mon, 20 Jan 2014 23:29:42 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752303AbaATW3j (ORCPT ); Mon, 20 Jan 2014 17:29:39 -0500 Received: from cloud.peff.net ([50.56.180.127]:35881 "HELO peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751380AbaATW3i (ORCPT ); Mon, 20 Jan 2014 17:29:38 -0500 Received: (qmail 17780 invoked by uid 102); 20 Jan 2014 22:29:37 -0000 Received: from c-71-63-4-13.hsd1.va.comcast.net (HELO sigill.intra.peff.net) (71.63.4.13) (smtp-auth username relayok, mechanism cram-md5) by peff.net (qpsmtpd/0.84) with ESMTPA; Mon, 20 Jan 2014 16:29:37 -0600 Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Mon, 20 Jan 2014 17:29:36 -0500 Content-Disposition: inline In-Reply-To: <20140120212845.GA11451@sigill.intra.peff.net> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On Mon, Jan 20, 2014 at 04:28:45PM -0500, Jeff King wrote: > [1/2]: t/perf: time rev-list with UNINTERESTING commits > [2/2]: list-objects: only look at cmdline trees with edge_hint > > Here's t/perf/p0001 output that shows the problem: > > 0001.5: rev-list --objects $commit --not --all > fbd4a703^ fbd4a703 HEAD > 0.04(0.04+0.00) 0.28(0.27+0.00) +600.0% 0.04(0.04+0.00) +0.0% Those numbers are on git.git. Obviously 600% is a lot, but 24ms is not. However, the cost is a factor of the tree size times the number of refs. For the "homebrew.git" repository stored at GitHub, which has ~28,000 refs (mostly pointing at pull-request tips in refs/pull), the numbers are much more dramatic: fbd4a703^ fbd4a703 HEAD 0.50(0.46+0.02) 8.23(8.17+0.06) +1546.0% 0.50(0.48+0.01) +0.0% -Peff