From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Ken Brown Newsgroups: gmane.emacs.bugs Subject: bug#16901: 24.3.50; emacs_backtrace.txt Date: Tue, 04 Mar 2014 09:23:39 -0500 Message-ID: <5315E1EB.8060404@cornell.edu> References: <831tylvkq2.fsf@gnu.org> <83lhwstu1k.fsf@gnu.org> <83ppm3rznz.fsf@gnu.org> <53150E29.7080504@cornell.edu> <83iorusk3h.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1393943051 26110 80.91.229.3 (4 Mar 2014 14:24:11 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 4 Mar 2014 14:24:11 +0000 (UTC) Cc: 16901@debbugs.gnu.org, lekktu@gmail.com, dmantipov@yandex.ru To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Tue Mar 04 15:24:18 2014 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1WKqGX-0007or-Kj for geb-bug-gnu-emacs@m.gmane.org; Tue, 04 Mar 2014 15:24:17 +0100 Original-Received: from localhost ([::1]:45259 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WKqGX-0006dc-2d for geb-bug-gnu-emacs@m.gmane.org; Tue, 04 Mar 2014 09:24:17 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:45946) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WKqGP-0006d5-Ik for bug-gnu-emacs@gnu.org; Tue, 04 Mar 2014 09:24:14 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WKqGJ-0001MO-RF for bug-gnu-emacs@gnu.org; Tue, 04 Mar 2014 09:24:09 -0500 Original-Received: from debbugs.gnu.org ([140.186.70.43]:48709) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WKqGJ-0001MI-N1 for bug-gnu-emacs@gnu.org; Tue, 04 Mar 2014 09:24:03 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1WKqGI-0001Hv-Bp for bug-gnu-emacs@gnu.org; Tue, 04 Mar 2014 09:24:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Ken Brown Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 04 Mar 2014 14:24:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 16901 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: moreinfo Original-Received: via spool by 16901-submit@debbugs.gnu.org id=B16901.13939430364936 (code B ref 16901); Tue, 04 Mar 2014 14:24:02 +0000 Original-Received: (at 16901) by debbugs.gnu.org; 4 Mar 2014 14:23:56 +0000 Original-Received: from localhost ([127.0.0.1]:49891 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1WKqGB-0001HV-6o for submit@debbugs.gnu.org; Tue, 04 Mar 2014 09:23:55 -0500 Original-Received: from limerock01.mail.cornell.edu ([128.84.12.99]:42624) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1WKqG8-0001HM-0W for 16901@debbugs.gnu.org; Tue, 04 Mar 2014 09:23:52 -0500 X-CornellRouted: This message has been Routed already. Original-Received: from authusersmtp.mail.cornell.edu (granite4.serverfarm.cornell.edu [10.16.197.9]) by limerock01.mail.cornell.edu (8.14.4/8.14.4_cu) with ESMTP id s24ENouR010072; Tue, 4 Mar 2014 09:23:51 -0500 Original-Received: from [192.168.1.5] (cpe-67-249-194-47.twcny.res.rr.com [67.249.194.47]) (authenticated bits=0) by authusersmtp.mail.cornell.edu (8.14.4/8.12.10) with ESMTP id s24ENnGo028277 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Tue, 4 Mar 2014 09:23:50 -0500 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 In-Reply-To: <83iorusk3h.fsf@gnu.org> X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:86529 Archived-At: On 3/3/2014 10:45 PM, Eli Zaretskii wrote: >> Date: Mon, 03 Mar 2014 18:20:09 -0500 >> From: Ken Brown >> CC: 16901@debbugs.gnu.org, dmantipov@yandex.ru >> >> If adj == 0 in line 1596, then we've allocated much more memory than >> we needed, and the next call to malloc (line 1602) allocates even >> more. And if adj == 1 in line 1596, then we've allocated exactly as >> much memory as we needed, so there's no need to call malloc again in >> line 1602. > > Thanks for reviewing. > > These are further optimizations, and can (and probably should) be done > in separate commits. But you aren't saying that the previous code was > correct, are you? No, I think it was clearly wrong. By accident, however, it probably worked most of the time and didn't waste memory, since adj is usually 0. When/if you do the optimizations I suggested, I think it would clarify the code if `adj' were used to represent the actual adjustment needed, something like this: adj = (uintptr_t) alignment - result % alignment; if (adj == alignment) adj = 0; Ken