From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: Nasty GC bug Date: Fri, 24 Aug 2012 01:56:17 -0700 Organization: UCLA Computer Science Department Message-ID: <503741B1.90600@cs.ucla.edu> References: <50372CC3.9050704@yandex.ru> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1345798591 2049 80.91.229.3 (24 Aug 2012 08:56:31 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 24 Aug 2012 08:56:31 +0000 (UTC) Cc: Emacs development discussions To: Dmitry Antipov Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Aug 24 10:56:31 2012 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1T4pgs-0003pZ-Rg for ged-emacs-devel@m.gmane.org; Fri, 24 Aug 2012 10:56:30 +0200 Original-Received: from localhost ([::1]:39103 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4pgr-0003V5-Ao for ged-emacs-devel@m.gmane.org; Fri, 24 Aug 2012 04:56:29 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:34420) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4pgj-0003Ux-1Z for emacs-devel@gnu.org; Fri, 24 Aug 2012 04:56:27 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T4pgc-0003Kz-Ao for emacs-devel@gnu.org; Fri, 24 Aug 2012 04:56:20 -0400 Original-Received: from smtp.cs.ucla.edu ([131.179.128.62]:33113) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4pgc-0003Kh-4v for emacs-devel@gnu.org; Fri, 24 Aug 2012 04:56:14 -0400 Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp.cs.ucla.edu (Postfix) with ESMTP id DCA0139E801A; Fri, 24 Aug 2012 01:56:12 -0700 (PDT) X-Virus-Scanned: amavisd-new at smtp.cs.ucla.edu Original-Received: from smtp.cs.ucla.edu ([127.0.0.1]) by localhost (smtp.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id LAoyMVWAd9L4; Fri, 24 Aug 2012 01:56:12 -0700 (PDT) Original-Received: from [192.168.1.3] (pool-108-23-119-2.lsanca.fios.verizon.net [108.23.119.2]) by smtp.cs.ucla.edu (Postfix) with ESMTPSA id 7179439E8017; Fri, 24 Aug 2012 01:56:12 -0700 (PDT) User-Agent: Mozilla/5.0 (X11; Linux i686; rv:14.0) Gecko/20120714 Thunderbird/14.0 In-Reply-To: <50372CC3.9050704@yandex.ru> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 131.179.128.62 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:152795 Archived-At: On 08/24/2012 12:26 AM, Dmitry Antipov wrote: > Suggested fix is to use MEM_TYPE_NON_LISP for spare memory, e.g.: Thanks for finding this bug. That patch doesn't look quite right if ! USE_LSB_TAG, since in that case lisp_align_malloc won't correctly report a failure in the section of code that checks whether the memory just allocated can be addressed through a Lisp object's pointer. Also, what about dont_register_blocks and allocated_mem_type? Instead, how about marking the spare conses with Vdead and the spare strings with NULL data? Admittedly I haven't had time to think this through....