From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Steudten Subject: Re: BUG: Kernel Panic: kernel-2.6.0-test9-bk21 for alpha in scsi context ll_rw_blk.c Date: Mon, 17 Nov 2003 22:34:46 +0100 Sender: linux-kernel-owner@vger.kernel.org Message-ID: <3FB93EF6.807@steudten.com> References: <3FB92938.8040906@steudten.com> <87r806d6n6.fsf@student.uni-tuebingen.de> Reply-To: alpha@steudten.com Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <87r806d6n6.fsf@student.uni-tuebingen.de> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Falk Hueffner Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, linux-alpha@vger.kernel.org On http://steudten.com/alpha/perf.php4 you can read: See prefetch section: The Alpha 21264 initiates a prefetch operation by executing one of the load instructions as summarized in the table below. Note that the destination register is R31 or F31. When used as a source register, R31 and F31 return integer zero and floating point zero, respectively. When used as a destination register as shown below, R31 and F31 denote the purpose of these instructions as a prefetch operation. Earlier Alpha implementations ignore these instructions. Some care must be taken as a prefetch with an invalid address must be dismissed by firmware and a prefetch can cause an alignment trap. Tom Falk Hueffner wrote: > Thomas Steudten writes: > > >>-> 0xfffffc0000476cb8 <__make_request+152>: lds $f31,0(t2) > > > The kernel is stupid, this is a prefetch, it should be totally ignored > if it is faulty. This is already handled for userspace accesses > IIRC... (I wonder why the PALcode doesn't already do that. Oh well.) > -- Tom LINUX user since kernel 0.99.x 1994. RPM Alpha packages at http://alpha.steudten.com/packages Want to know what S.u.S.E 1995 cdrom-set contains?