From owner-freebsd-alpha@FreeBSD.ORG Wed Apr 28 07:16:06 2004 Return-Path: Delivered-To: freebsd-alpha@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7459D16A4CE; Wed, 28 Apr 2004 07:16:06 -0700 (PDT) Received: from duke.cs.duke.edu (duke.cs.duke.edu [152.3.140.1]) by mx1.FreeBSD.org (Postfix) with ESMTP id 09F5C43D46; Wed, 28 Apr 2004 07:16:06 -0700 (PDT) (envelope-from gallatin@cs.duke.edu) Received: from grasshopper.cs.duke.edu (grasshopper.cs.duke.edu [152.3.145.30]) by duke.cs.duke.edu (8.12.10/8.12.10) with ESMTP id i3SEG5xZ020363 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 28 Apr 2004 10:16:05 -0400 (EDT) Received: (from gallatin@localhost) by grasshopper.cs.duke.edu (8.12.9p2/8.12.9/Submit) id i3SEG05T086899; Wed, 28 Apr 2004 10:16:00 -0400 (EDT) (envelope-from gallatin) From: Andrew Gallatin MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16527.48288.319462.214843@grasshopper.cs.duke.edu> Date: Wed, 28 Apr 2004 10:16:00 -0400 (EDT) To: Ruslan Ermilov In-Reply-To: <20040428135850.GA43106@ip.net.ua> References: <20040428084120.GA25958@ip.net.ua> <16527.42479.941859.703698@grasshopper.cs.duke.edu> <20040428135850.GA43106@ip.net.ua> X-Mailer: VM 6.75 under 21.1 (patch 12) "Channel Islands" XEmacs Lucid cc: Alan Cox cc: alpha@FreeBSD.org Subject: Re: pmap_emulate_reference() panics still ongoing X-BeenThere: freebsd-alpha@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Porting FreeBSD to the Alpha List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Apr 2004 14:16:06 -0000 Ruslan Ermilov writes: > On Wed, Apr 28, 2004 at 08:39:11AM -0400, Andrew Gallatin wrote: > > > > Ruslan Ermilov writes: > > > Andrew, > > > > > > This is with latest src/sys/alpha/alpha/pmap.c,v 1.146. > > > > > > db> where > > > Debugger() at Debugger+0x38 > > > __panic() at __panic+0x228 > > > pmap_emulate_reference() at pmap_emulate_reference+0x15c > > > trap() at trap+0x3dc > > > XentMM() at XentMM+0x2c > > > --- memory management fault (from ipl 0) --- > > > --- user mode --- > > > > Damn. Did the change make it any worse for you? > > > No, I can't say this made things any worse. ;) Good. > This is not a very fast runner (166MHz EV4, 64MB RAM, swap > is used). Since I've upgraded it to 5-CURRENT, running the > GENERIC kernel, my 5 attempts to build world ended up with > this panic (often the panic message was unreadable, this one, > after I've upgraded kernel to the latest pmap.c, was probably > a good exception). Now I've built the debug version of the > kernel. Will it be of some help? Wow, and I thought my 600MHz ev67 was slow. At least you can reproduce this -- I can't. Given that I always run a bwx-enabled kernel, and I never see it, I wonder if there might be some corruption caused by 8 or 16 bit data fields in the vm or pmap systems which share a 32-bit word, but which are separately locked. I'm thinking that the read-modify-write which a non bwx kernel needs to do could lead to data-corruption in this case. I don't see anything immediately, but then I don't know the vm system very well. > (Hardly relevant, but it was happy running 4.10-RC.) Very relevant -- it means the bug is new to 5.x Drew