From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: Article about "git bisect run" on LWN Date: Fri, 6 Feb 2009 02:52:15 +0100 Message-ID: <20090206015215.GA6261@elte.hu> References: <200902050747.50100.chriscool@tuxfamily.org> <20090205141336.GA28443@elte.hu> <20090206014655.GA26807@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christian Couder , git@vger.kernel.org, Junio C Hamano , Andreas Ericsson , Jeff Garzik , Linus Torvalds , Bill Lear , Jon Seymour , Johannes Schindelin To: david@lang.hm X-From: git-owner@vger.kernel.org Fri Feb 06 02:53:58 2009 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 1LVFun-0002Sy-AW for gcvg-git-2@gmane.org; Fri, 06 Feb 2009 02:53:57 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752659AbZBFBwb (ORCPT ); Thu, 5 Feb 2009 20:52:31 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752650AbZBFBwb (ORCPT ); Thu, 5 Feb 2009 20:52:31 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:48435 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750885AbZBFBwa (ORCPT ); Thu, 5 Feb 2009 20:52:30 -0500 Received: from elvis.elte.hu ([157.181.1.14]) by mx2.mail.elte.hu with esmtp (Exim) id 1LVFtC-0000xN-Ov from ; Fri, 06 Feb 2009 02:52:21 +0100 Received: by elvis.elte.hu (Postfix, from userid 1004) id 360263E21B0; Fri, 6 Feb 2009 02:52:16 +0100 (CET) Content-Disposition: inline In-Reply-To: <20090206014655.GA26807@elte.hu> User-Agent: Mutt/1.5.18 (2008-05-17) Received-SPF: neutral (mx2: 157.181.1.14 is neither permitted nor denied by domain of elte.hu) client-ip=157.181.1.14; envelope-from=mingo@elte.hu; helo=elvis.elte.hu; X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: * Ingo Molnar wrote: > The idea would be to insert 30% redunancy into my bisections automatically > - so that i could trust _all_ bisections more - not just the ones i > suspect to be non-deterministic. Hence the suggestion to enable lower > levels of redundancy like 30%. (but even 10% or 20% might be enough to > weed out the most obvious cases) the other advantage of redundancy that i forgot to mention: - Sometimes the non-determinism is inserted by a _human_. It happened not once that i accidentally mis-judged a testpoint, and the bisection ran afoul. Only 4-5 steps later do i suspect that something is wrong: that i get an unlikely series of good,good,good,good,good or bad,bad,bad,bad,bad testpoint qualities. So for manual bisection, redundancy can be a big time-saver. If i mess up a bisection point then say 50% redundancy can still point out my stupidity with a high likelyhood. In fact if Git sees an unlikely series of same-quality bisection points, it could artificially insert a test to around the last-different test point, to test the theory of a messed up bisection. Ingo