From owner-freebsd-java@FreeBSD.ORG Thu Apr 20 01:20:15 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 4BF9716A405 for ; Thu, 20 Apr 2006 01:20:15 +0000 (UTC) (envelope-from kurt@intricatesoftware.com) Received: from mta6.srv.hcvlny.cv.net (mta6.srv.hcvlny.cv.net [167.206.4.201]) by mx1.FreeBSD.org (Postfix) with ESMTP id D671E43D4C for ; Thu, 20 Apr 2006 01:20:12 +0000 (GMT) (envelope-from kurt@intricatesoftware.com) Received: from [172.16.1.72] (ool-457a77e8.dyn.optonline.net [69.122.119.232]) by mta6.srv.hcvlny.cv.net (Sun Java System Messaging Server 6.2-4.03 (built Sep 22 2005)) with ESMTP id <0IXZ0026JYDNEO30@mta6.srv.hcvlny.cv.net> for freebsd-java@freebsd.org; Wed, 19 Apr 2006 21:20:11 -0400 (EDT) Date: Wed, 19 Apr 2006 21:20:10 -0400 From: Kurt Miller In-reply-to: <4446BE1A.6070101@bahnhofbredband.se> To: freebsd-java@freebsd.org Message-id: <200604192120.10697.kurt@intricatesoftware.com> MIME-version: 1.0 Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: 7BIT Content-disposition: inline References: <200604101315.12391.lists@intricatesoftware.com> <4446BE1A.6070101@bahnhofbredband.se> User-Agent: KMail/1.9.1 Cc: Carl Johan Gustavsson 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: Thu, 20 Apr 2006 01:20:15 -0000 On Wednesday 19 April 2006 6:47 pm, Carl Johan Gustavsson wrote: > 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. > > How can I make this option default? I'm using 6.1-PRE. I guess you could add it to the /usr/local/bin/javavm script. -Kurt