Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756183Ab1DAUWd (ORCPT ); Fri, 1 Apr 2011 16:22:33 -0400 Received: from terminus.zytor.com ([198.137.202.10]:45936 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755629Ab1DAUW2 (ORCPT ); Fri, 1 Apr 2011 16:22:28 -0400 Message-ID: <4D9633E7.1010707@zytor.com> Date: Fri, 01 Apr 2011 13:21:59 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.15) Gecko/20110307 Fedora/3.1.9-0.39.b3pre.fc14 Thunderbird/3.1.9 MIME-Version: 1.0 To: Yinghai Lu CC: Stefano Stabellini , Ingo Molnar , "Rafael J. Wysocki" , Michael Leun , "linux-kernel@vger.kernel.org" , Greg Kroah-Hartman , Mike Pagano Subject: Re: 2.6.38.2 breaks suspend to disk References: <20110330203215.0a1a41a7@xenia.leun.net> <20110331090524.07ad0069@xenia.leun.net> <201103312348.53678.rjw@sisk.pl> <4D94FE37.8070109@kernel.org> <4D95F80D.7070201@kernel.org> <4D95FBDD.9050901@zytor.com> <4D961FBC.2030105@zytor.com> <4D962837.2070300@kernel.org> <4D96294B.5050909@zytor.com> <4D962D72.2010501@kernel.org> In-Reply-To: <4D962D72.2010501@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 726 Lines: 24 On 04/01/2011 12:54 PM, Yinghai Lu wrote: > > ok, please check if you are happy with this one. > The best would simply be: mmu_cr4_features = read_cr4_safe(); If this has to run before we can handle exceptions, one can verify the existence by testing for the CPUID instruction (a CPU has CR4 if and only if it has CPUID): if (boot_cpu_data.cpuid_level >= 0) mmu_cr4_features = read_cr4_safe(); ... since we set cpuid_level to -1 if there is no CPUID instruction. -hpa -- 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/