From owner-freebsd-java@FreeBSD.ORG Wed Apr 19 22:48:28 2006 Return-Path: X-Original-To: freebsd-java@freebsd.org Delivered-To: freebsd-java@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9774216A405 for ; Wed, 19 Apr 2006 22:48:28 +0000 (UTC) (envelope-from carl.gustavsson@bahnhofbredband.se) Received: from mx1.kth.se (mx1.kth.se [130.237.32.140]) by mx1.FreeBSD.org (Postfix) with ESMTP id 12F1443D46 for ; Wed, 19 Apr 2006 22:48:24 +0000 (GMT) (envelope-from carl.gustavsson@bahnhofbredband.se) Received: from localhost (localhost.localdomain [127.0.0.1]) by mx1.kth.se (Postfix) with ESMTP id E9843141C84; Thu, 20 Apr 2006 00:48:22 +0200 (CEST) Received: from mx1.kth.se ([127.0.0.1]) by localhost (mx1.kth.se [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 14456-01-90; Thu, 20 Apr 2006 00:48:21 +0200 (CEST) Received: from [192.168.0.9] (c213-100-49-147.swipnet.se [213.100.49.147]) by mx1.kth.se (Postfix) with ESMTP id B3543141C82; Thu, 20 Apr 2006 00:48:21 +0200 (CEST) Message-ID: <4446BE1A.6070101@bahnhofbredband.se> Date: Thu, 20 Apr 2006 00:47:54 +0200 From: Carl Johan Gustavsson User-Agent: Thunderbird 1.5 (X11/20060220) MIME-Version: 1.0 To: kurt@intricatesoftware.com References: <200604101315.12391.lists@intricatesoftware.com> In-Reply-To: <200604101315.12391.lists@intricatesoftware.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: by amavisd-new at kth.se Cc: freebsd-java@freebsd.org Subject: Re: Diablo 1.5 SIGBUS - fixed X-BeenThere: freebsd-java@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting Java to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Apr 2006 22:48:28 -0000 Kurt Miller wrote: > The SIGBUS occurred in a thread related optimization for > multiprocessor systems that Sun introduced after the initial > release of 1.5.0. From what I can gather from a brief > inspection of the code is that they were removing unnecessary > memory barriers, but added the UseMembar option to have a > way to enable them again. The SIGBUS was happening in the > new optimized code path that didn't use a membar. > > The best description I've found so far on the use of > membar is in this old bug report: > > http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4629468 > > The following excerpt was the most relevant, "For MP systems, > a membar may still be required so that the load or store is seen > in the order desired across a machine's memory system. It depends > on the memory system." > > In other bug reports I see that on Windows for the 1.5.0_0x > releases -XX:+UseMembar is the default because of problems with > the changes. So diablo on multiprocessor systems will need to use > -XX:+UseMembar until the next release where it can be made the > default. > > -Kurt > _______________________________________________ > freebsd-java@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-java > To unsubscribe, send any mail to "freebsd-java-unsubscribe@freebsd.org" > How can I make this option default? I'm using 6.1-PRE. Thanks Carl Johan Gustavsson