Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751193AbVJLCNS (ORCPT ); Tue, 11 Oct 2005 22:13:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751261AbVJLCNS (ORCPT ); Tue, 11 Oct 2005 22:13:18 -0400 Received: from zctfs063.nortelnetworks.com ([47.164.128.120]:58516 "EHLO zctfs063.nortelnetworks.com") by vger.kernel.org with ESMTP id S1751193AbVJLCNS (ORCPT ); Tue, 11 Oct 2005 22:13:18 -0400 Message-ID: <434C710C.2040305@nortel.com> Date: Tue, 11 Oct 2005 20:12:28 -0600 From: "Christopher Friesen" User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040115 X-Accept-Language: en-us, en MIME-Version: 1.0 To: linux@horizon.com CC: dev@sw.ru, linux-kernel@vger.kernel.org Subject: Re: SMP syncronization on AMD processors (broken?) References: <20051011235017.21719.qmail@science.horizon.com> In-Reply-To: <20051011235017.21719.qmail@science.horizon.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 12 Oct 2005 02:12:38.0534 (UTC) FILETIME=[6B1B6A60:01C5CED2] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 697 Lines: 18 linux@horizon.com wrote: > The right thing to do here is to wait for the flag to be set *outside* > the lock, and then re-validate inside the lock: This may work on some processors, but on others the read of "progress" in XXX, or the write in YYY may require arch-specific code to force the update out to other cpus. Alternately, explicitly atomic operations should suffice, but a simple increment is probably not enough for portable code. Chris - 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/