From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Dmitry Antipov Newsgroups: gmane.emacs.devel Subject: Re: Nasty GC bug Date: Fri, 24 Aug 2012 14:58:18 +0400 Message-ID: <50375E4A.2030506@yandex.ru> References: <50372CC3.9050704@yandex.ru> <503741B1.90600@cs.ucla.edu> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1345805764 27581 80.91.229.3 (24 Aug 2012 10:56:04 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 24 Aug 2012 10:56:04 +0000 (UTC) Cc: Emacs development discussions To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Aug 24 12:56:03 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 1T4rYV-0002ov-Ti for ged-emacs-devel@m.gmane.org; Fri, 24 Aug 2012 12:56:00 +0200 Original-Received: from localhost ([::1]:48161 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4rYU-0002T0-AZ for ged-emacs-devel@m.gmane.org; Fri, 24 Aug 2012 06:55:58 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:47435) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4rYR-0002Su-Po for emacs-devel@gnu.org; Fri, 24 Aug 2012 06:55:56 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T4rYK-0004oC-OH for emacs-devel@gnu.org; Fri, 24 Aug 2012 06:55:55 -0400 Original-Received: from forward16.mail.yandex.net ([95.108.253.141]:56482) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4rYK-0004nw-By for emacs-devel@gnu.org; Fri, 24 Aug 2012 06:55:48 -0400 Original-Received: from smtp17.mail.yandex.net (smtp17.mail.yandex.net [95.108.252.17]) by forward16.mail.yandex.net (Yandex) with ESMTP id A07EFD21B59; Fri, 24 Aug 2012 14:55:45 +0400 (MSK) Original-Received: from smtp17.mail.yandex.net (localhost [127.0.0.1]) by smtp17.mail.yandex.net (Yandex) with ESMTP id 7B0A51900018; Fri, 24 Aug 2012 14:55:45 +0400 (MSK) Original-Received: from unknown (unknown [37.139.84.55]) by smtp17.mail.yandex.net (nwsmtp/Yandex) with ESMTP id tiE0Fmki-tjE0QYjd; Fri, 24 Aug 2012 14:55:45 +0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1345805745; bh=D/aeejlqLv1g+/bkbRO1zLemrUvvOT2nOp4U0AO0X44=; h=Message-ID:Date:From:User-Agent:MIME-Version:To:CC:Subject: References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=nMgTMmyvteoYOzcggPOA3ioZMi/B6OT3vL4w54Sw5DzgCFvcsR5k8/ipZPDsnQCPU J66Q5VmUCchWk8yivmyscRh531Vo9uf5idgKVFqdbJjhIWrknR2utBKa9t8dJ25qJA OwX51lf9o6GIQfJcQm8AK4RJVBI99gQV2m1Vo9gQ= User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120713 Thunderbird/14.0 In-Reply-To: <503741B1.90600@cs.ucla.edu> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 95.108.253.141 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:152800 Archived-At: On 08/24/2012 12:56 PM, Paul Eggert wrote: > 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.... This implies initialization of the data which we will never use; what about the special memory type, e.g. MEM_TYPE_SPARE? Dmitry