From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jakub Narebski Subject: Re: [PATCH v3 0/3] automatically skip away from broken commits Date: Tue, 09 Jun 2009 03:02:02 -0700 (PDT) Message-ID: References: <20090606043853.4031.78284.chriscool@tuxfamily.org> <7vskidcf9s.fsf@alter.siamese.dyndns.org> <200906070932.36913.chriscool@tuxfamily.org> <4A2CAA56.1030707@zytor.com> <7vws7n6vcf.fsf@alter.siamese.dyndns.org> <4A2D337C.70203@zytor.com> <7vzlcixwue.fsf@alter.siamese.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Junio C Hamano , "H. Peter Anvin" , Christian Couder , git@vger.kernel.org, Sam Vilain , Ingo Molnar To: Christian Couder X-From: git-owner@vger.kernel.org Tue Jun 09 12:02:16 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 1MDy9l-0001l5-50 for gcvg-git-2@gmane.org; Tue, 09 Jun 2009 12:02:13 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757991AbZFIKCF convert rfc822-to-quoted-printable (ORCPT ); Tue, 9 Jun 2009 06:02:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757279AbZFIKCE (ORCPT ); Tue, 9 Jun 2009 06:02:04 -0400 Received: from mail-ew0-f210.google.com ([209.85.219.210]:35844 "EHLO mail-ew0-f210.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755168AbZFIKCC convert rfc822-to-8bit (ORCPT ); Tue, 9 Jun 2009 06:02:02 -0400 Received: by ewy6 with SMTP id 6so5020236ewy.37 for ; Tue, 09 Jun 2009 03:02:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:received:received :x-authentication-warning:to:cc:subject:references:from:date :in-reply-to:message-id:lines:user-agent:mime-version:content-type :content-transfer-encoding; bh=iSdFJZKFZTysr/yvLlVAsepkSb6GrTJjoVevD5yDcvA=; b=FfNd1Ta4P1ZS32u8MWE94X3e2aVLsLiswErARf06oYBrAEQ2sdkRS0LS8o3SF+JPs8 SxEI0ZZSXooP7OGMSmmKhvskhIZcDKzaft8PMx+Jdo3k5d91R/a9HnjyGU1UD19IHqx8 KEyALLtT/iyKLwmg8JW4mXvFDB3YOaaXK57SY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=x-authentication-warning:to:cc:subject:references:from:date :in-reply-to:message-id:lines:user-agent:mime-version:content-type :content-transfer-encoding; b=sGOPiEerp536FXv/c2Yi+Amr82ZWIM2PfIEUODEEkslqNrAaUBm+ybkR3ZocOvvR1O v+ooprAc9r796IcmgS/MY/gldsujQY/N7A40ubQl52SpjgbpQvTCp8STM1OU40WosWr9 OcGUNGT7NvRoSVIv95hgvrcYUhEU7TKY139QA= Received: by 10.210.36.8 with SMTP id j8mr2165241ebj.40.1244541723323; Tue, 09 Jun 2009 03:02:03 -0700 (PDT) Received: from localhost.localdomain (abvq34.neoplus.adsl.tpnet.pl [83.8.214.34]) by mx.google.com with ESMTPS id 28sm1482476eyg.54.2009.06.09.03.02.01 (version=TLSv1/SSLv3 cipher=RC4-MD5); Tue, 09 Jun 2009 03:02:02 -0700 (PDT) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by localhost.localdomain (8.13.4/8.13.4) with ESMTP id n59A6rfo008006; Tue, 9 Jun 2009 12:06:54 +0200 Received: (from jnareb@localhost) by localhost.localdomain (8.13.4/8.13.4/Submit) id n59A6poA008003; Tue, 9 Jun 2009 12:06:51 +0200 X-Authentication-Warning: localhost.localdomain: jnareb set sender to jnareb@gmail.com using -f In-Reply-To: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Christian Couder writes: > On Mon, Jun 8, 2009 at 11:02 PM, Junio C Hamano wr= ote: >> "H. Peter Anvin" writes: >> >>> The advantage of that -- and I have to admit I don't know if it wil= l >>> ever matter in practice -- is that using an actual PRNG: >>> >>> a) is less likely to get into pathological capture behaviors. >>> b) doesn't make people think later that there is something magic to= the >>> =A0 =A0arbitrary chosen numbers. >> >> My gut feeling agrees with you that both are likely to be true; thes= e are >> good points. >> >> Christian, what do you think? >=20 > Here are some reasons why I think my algorithm might be better: >=20 > - using HPA's formula I get on average 0.86 bits of information at > each step when alternating (against 0.72 when using a PRNG) > - I think that if the branches in the graph merge often between each > other, then on a big scale it's like when you are on the linear case > - I don't think we should try too hard to avoid pathological capture > behaviors, because I think we can't avoid them anyway in some cases, > like if the first bad commit is near many untestable commits By the way, I have asked question about best algorithm for "bisect skip= " on StackOverflow[1], but didn't get (yet) any good responses... [1]: http://stackoverflow.com/questions/959324/ --=20 Jakub Narebski Poland ShadeHawk on #git