Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266181AbUA1UbF (ORCPT ); Wed, 28 Jan 2004 15:31:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266175AbUA1UbF (ORCPT ); Wed, 28 Jan 2004 15:31:05 -0500 Received: from fw.osdl.org ([65.172.181.6]:34509 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S266173AbUA1Uaz (ORCPT ); Wed, 28 Jan 2004 15:30:55 -0500 Date: Wed, 28 Jan 2004 12:30:48 -0800 (PST) From: Linus Torvalds To: Andi Kleen cc: willy@debian.org, ishii.hironobu@jp.fujitsu.com, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org Subject: Re: [RFC/PATCH, 2/4] readX_check() performance evaluation In-Reply-To: Message-ID: References: <00a301c3e541$c13a6350$2987110a@lsd.css.fujitsu.com> <20040128182003.GL11844@parcelfarce.linux.theplanet.co.uk> <20040128204049.627e6312.ak@suse.de> <20040128211554.0cc890fb.ak@suse.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1140 Lines: 27 On Wed, 28 Jan 2004, Linus Torvalds wrote: > > If the real error is on the bridge somewhere but you don't even know which > CPU did the access (and just "somebody" gets an MCE), just set a global > flag, and have "read_pcix_error()" check the bridge (since it doesn't need > to look anything up - it already knows the device). > > And in that case then you need to take the proper locks (per-bridge, or > global, depending on just how much you care) in "clear_pcix_error()" and > release them in "read_pcix_error()". Note, in case this wasn't clear already: in this case, the "MCE flag" is just a lazy flag saying "you need to check more deeply". It wouldn't cause false positives, simply because the _real_ check ends up being "read_pcix_error()" actually reading the error status from the bridge or the device. It's just that 99% of the time, you don't want to do even that. Linus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/