Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756750AbXELE34 (ORCPT ); Sat, 12 May 2007 00:29:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755200AbXELE3t (ORCPT ); Sat, 12 May 2007 00:29:49 -0400 Received: from srv5.dvmed.net ([207.36.208.214]:45905 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752897AbXELE3s (ORCPT ); Sat, 12 May 2007 00:29:48 -0400 Message-ID: <464542B1.3040403@garzik.org> Date: Sat, 12 May 2007 00:29:37 -0400 From: Jeff Garzik User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: Satyam Sharma CC: Jonathan Corbet , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Johannes Stezenbach , Jesper Juhl , Randy Dunlap , Heikki Orsila , "H. Peter Anvin" , jimmy bahuleyan , Stefan Richter Subject: Re: [PATCH] "volatile considered harmful", take 3 References: <12700.1178905000@lwn.net> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -4.3 (----) X-Spam-Report: SpamAssassin version 3.1.8 on srv5.dvmed.net summary: Content analysis details: (-4.3 points, 5.0 required) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1014 Lines: 27 Satyam Sharma wrote: > On 5/11/07, Jonathan Corbet wrote: >> + - Pointers to data structures in coherent memory which might be >> modified >> + by I/O devices can, sometimes, legitimately be volatile. A ring >> buffer >> + used by a network adapter, where that adapter changes pointers to >> + indicate which descriptors have been processed, is an example of >> this >> + type of situation. > > is a legitimate use case for volatile is still not clear to me (I IMO it is not. We do /not/ want to encourage volatile use in those cases, and indeed, it's not necessary even if you can rationalize the use of the English word "volatile" to describe the situation. Drivers work quite well without volatile in such situations. Jeff - 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/