Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266033AbUA1QPq (ORCPT ); Wed, 28 Jan 2004 11:15:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266048AbUA1QPq (ORCPT ); Wed, 28 Jan 2004 11:15:46 -0500 Received: from fw.osdl.org ([65.172.181.6]:43668 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S266033AbUA1QPn (ORCPT ); Wed, 28 Jan 2004 11:15:43 -0500 Date: Wed, 28 Jan 2004 08:15:22 -0800 (PST) From: Linus Torvalds To: Russell King cc: Hironobu Ishii , linux-kernel , linux-ia64 Subject: Re: [RFC/PATCH, 2/4] readX_check() performance evaluation In-Reply-To: <20040128085825.A3591@flint.arm.linux.org.uk> Message-ID: References: <00a301c3e541$c13a6350$2987110a@lsd.css.fujitsu.com> <20040128085825.A3591@flint.arm.linux.org.uk> 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: 1039 Lines: 27 On Wed, 28 Jan 2004, Russell King wrote: > > What if the failing PCI access happened in an interrupt routine? > (I'm thinking of the situation where you may need to read the PCI > status registers to find out whether an error occurred.) > > Also, for that matter, what if a network device receives an abort > while performing BM-DMA? > > Do we even care about either of these two scenarios? We do, and the people who care about readX_check() had better be careful. Quite possibly the "clear_pcix_error()" has to get a lock and disable interrupts, and the "read_pcix_error()" routine would release the lock. But that depends on the hardware - details like whether hardware can track individual errors on multiple CPU's or not. And keep in mind, 99% of all people won't ever care. 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/