Return-Path: Delivered-To: apmail-incubator-stdcxx-dev-archive@www.apache.org Received: (qmail 78353 invoked from network); 17 Oct 2007 20:16:20 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 17 Oct 2007 20:16:20 -0000 Received: (qmail 28012 invoked by uid 500); 17 Oct 2007 20:06:55 -0000 Delivered-To: apmail-incubator-stdcxx-dev-archive@incubator.apache.org Received: (qmail 27998 invoked by uid 500); 17 Oct 2007 20:06:55 -0000 Mailing-List: contact stdcxx-dev-help@incubator.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: stdcxx-dev@incubator.apache.org Delivered-To: mailing list stdcxx-dev@incubator.apache.org Received: (qmail 27984 invoked by uid 99); 17 Oct 2007 20:06:55 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 17 Oct 2007 13:06:55 -0700 X-ASF-Spam-Status: No, hits=-0.0 required=10.0 tests=SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: local policy) Received: from [208.30.140.160] (HELO moroha.quovadx.com) (208.30.140.160) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 17 Oct 2007 20:06:59 +0000 Received: from qxvcexch01.ad.quovadx.com ([192.168.170.59]) by moroha.quovadx.com (8.13.6/8.13.6) with ESMTP id l9HK5wCv029812 for ; Wed, 17 Oct 2007 20:05:58 GMT Received: from [10.70.3.143] ([10.70.3.143]) by qxvcexch01.ad.quovadx.com with Microsoft SMTPSVC(6.0.3790.1830); Wed, 17 Oct 2007 14:05:10 -0600 Message-ID: <47166B4D.2000506@roguewave.com> Date: Wed, 17 Oct 2007 14:06:37 -0600 From: Martin Sebor User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.6) Gecko/20070802 SeaMonkey/1.1.4 MIME-Version: 1.0 To: stdcxx-dev@incubator.apache.org Subject: Re: stdcxx 4.2.0/4.1.3 binary incompatibility on Linux References: <471644A7.9050101@roguewave.com> <47164C7F.5050106@roguewave.com> <471659D7.6020109@roguewave.com> <2494433f0710171239mcbd53cfs8cc025aec2a04da4@mail.gmail.com> In-Reply-To: <2494433f0710171239mcbd53cfs8cc025aec2a04da4@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 17 Oct 2007 20:05:10.0817 (UTC) FILETIME=[05ACC910:01C810F9] X-Virus-Checked: Checked by ClamAV on apache.org Mark Brown wrote: > On 10/17/07, Martin Sebor wrote: >> Okay, I've got it: >> >> http://issues.apache.org/jira/browse/STDCXX-162 >> >> Damn that was hard! >> >> So, what do we do? Going back to using a mutex for strings would >> be *huge* performance hit on one of the most popular platforms >> (if not the most popular one), but then again, keeping the status >> quo will break binary compatibility on the (now) most popular >> platform. >> >> Opinions? > > Maybe it isn't as bad as you think. Have you done any measurements of > the performance difference between the previous version and 4.2.0? It is quite bad. Here are timings for 4 threads (running on a 4 CPU dual core Xeon) copying the same global string object 5 million times: 4.1.x 4.2.0 real 0m38.464s 0m 8.660s user 0m26.685s 0m33.655s sys 1m54.129s 0m 0.001s I was hoping that stdcxx 4.1.2 wouldn't build on x86_64 and that the platform would be new for 4.1.3 (and could thought of as experimental, giving us a possible excuse to break compatibility) but no such luck. It builds fine and has the mutex in it, just like 4.1.3. Martin > > -- Mark