From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Jim Meyering Newsgroups: gmane.emacs.devel Subject: Re: Nasty GC bug Date: Mon, 27 Aug 2012 15:25:54 +0200 Message-ID: <87a9xgjwkd.fsf@rho.meyering.net> References: <50372CC3.9050704@yandex.ru> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1346073974 25358 80.91.229.3 (27 Aug 2012 13:26:14 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 27 Aug 2012 13:26:14 +0000 (UTC) Cc: Emacs development discussions To: Dmitry Antipov Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Aug 27 15:26:15 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 1T5zKY-00022Z-59 for ged-emacs-devel@m.gmane.org; Mon, 27 Aug 2012 15:26:14 +0200 Original-Received: from localhost ([::1]:54895 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T5zKW-0005Dk-5N for ged-emacs-devel@m.gmane.org; Mon, 27 Aug 2012 09:26:12 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:56556) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T5zKN-0005DT-Fh for emacs-devel@gnu.org; Mon, 27 Aug 2012 09:26:10 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T5zKF-0000Wv-JF for emacs-devel@gnu.org; Mon, 27 Aug 2012 09:26:03 -0400 Original-Received: from mx.meyering.net ([88.168.87.75]:51250) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T5zKF-0000Wq-C0 for emacs-devel@gnu.org; Mon, 27 Aug 2012 09:25:55 -0400 Original-Received: from rho.meyering.net (rho.meyering.net [127.0.0.1]) by rho.meyering.net (Acme Bit-Twister) with ESMTP id A8855602A6; Mon, 27 Aug 2012 15:25:54 +0200 (CEST) In-Reply-To: <50372CC3.9050704@yandex.ru> (Dmitry Antipov's message of "Fri, 24 Aug 2012 11:26:59 +0400") Original-Lines: 10 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 88.168.87.75 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:152866 Archived-At: Dmitry Antipov wrote: > It looks like live_cons_p (M, P) may be true if P is a cons cell from > the spare_memory[X], X = 1..4. So, mark_maybe_{object, pointer} may > call to mark_object for an uninitialized cons from spare blocks, with > random results (most probably a crash). This is very hard to reproduce > because it depends from the values found on a C stack. Nice work! I wouldn't be surprised if this is the cause of some of the GC-related problems I've reported over the last year or two.