From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 20 Oct 2005 11:49:26 +0100 (BST) Received: from extgw-uk.mips.com ([62.254.210.129]:13318 "EHLO bacchus.net.dhis.org") by ftp.linux-mips.org with ESMTP id S3465685AbVJTKtK (ORCPT ); Thu, 20 Oct 2005 11:49:10 +0100 Received: from dea.linux-mips.net (localhost.localdomain [127.0.0.1]) by bacchus.net.dhis.org (8.13.4/8.13.1) with ESMTP id j9KAn2eP010147; Thu, 20 Oct 2005 11:49:02 +0100 Received: (from ralf@localhost) by dea.linux-mips.net (8.13.4/8.13.4/Submit) id j9KAn2C6010146; Thu, 20 Oct 2005 11:49:02 +0100 Date: Thu, 20 Oct 2005 11:49:02 +0100 From: Ralf Baechle To: Andrew Isaacson Cc: linux-mips@linux-mips.org Subject: Re: [PATCH 8/12] cerr-printk-not-prom-printf Message-ID: <20051020104902.GA9491@linux-mips.org> References: <20051020065320.GA23857@broadcom.com> <20051020065757.GH23899@broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20051020065757.GH23899@broadcom.com> User-Agent: Mutt/1.4.2.1i Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 9303 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: ralf@linux-mips.org Precedence: bulk X-list: linux-mips On Wed, Oct 19, 2005 at 11:57:57PM -0700, Andrew Isaacson wrote: > Use printk rather than prom_printf in cache error handlers. > prom_printf does not handle SMP locking, and shows up only > on console (not in dmesg(1) or syslog). This patch essentially reverses http://www.linux-mips.org/git?p=linux.git;a=blobdiff;h=b2d41a2b0c406db6be87d02f51600e7e3013a748;hp=051290842231d9734d0bb2dc4c56b8590c4f5337;hb=760190d3f99ebabd965bd35324d5d084ff266711;f=arch/mips/mm/cerr-sb1.c (Yuck, gitk URLs are bloody long ...) The reason for this old commit was that this code is running uncached, so the operation of ll/sc in the spinlocks is undefined according to the MIPS64 spec, also there is a potencial deadlock since printk's logbuf_lock might be held. The old pass 1 part did truely exercise the cache error handler ;-) Ralf