Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161458AbXBGWXw (ORCPT ); Wed, 7 Feb 2007 17:23:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161455AbXBGWXw (ORCPT ); Wed, 7 Feb 2007 17:23:52 -0500 Received: from smtp-outbound-1.vmware.com ([65.113.40.141]:41672 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1161454AbXBGWXv (ORCPT ); Wed, 7 Feb 2007 17:23:51 -0500 Message-ID: <45CA5176.4000306@vmware.com> Date: Wed, 07 Feb 2007 14:23:50 -0800 From: Zachary Amsden User-Agent: Thunderbird 1.5.0.9 (X11/20061206) MIME-Version: 1.0 To: Rusty Russell CC: Pavel Machek , Andi Kleen , Linux Kernel Mailing List , Andrew Morton , Jeremy Fitzhardinge , Chris Wright Subject: Re: [PATCH 9/11] Panic delay fix References: <200702060353.l163rUmj000771@zach-dev.vmware.com> <20070206122729.GC47229@muc.de> <45C8FA2D.6010706@vmware.com> <20070207123552.GD4481@ucw.cz> <1170880572.11736.4.camel@localhost.localdomain> In-Reply-To: <1170880572.11736.4.camel@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1119 Lines: 28 Rusty Russell wrote: > On Wed, 2007-02-07 at 12:35 +0000, Pavel Machek wrote: > >> Ugh, it sounds like paravirt is more b0rken then I thought. It should >> always to the proper delay, then replace those udelays that are not >> needed on virtualized hardware with something else. >> >> Just magically defining udelay into nop is broken. >> > > We'd have to audit and figure out what udelays are for hardware and > which are not, but the evidence is that the vast majority of them are > for hardware and not needed for virtualization. > > Changing udelay to "hardware_udelay" or something all over the kernel > would have delayed the paravirt_ops merge by an infinite amount 8) > Yes, so I chose the same approach used for b0rken hardware - #define REALLY_SLOW_IO before including headers. It's ugly, but it works without rewriting the entire source base. Zach - 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/