Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755787Ab1DBAKk (ORCPT ); Fri, 1 Apr 2011 20:10:40 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:53749 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755625Ab1DBAKj (ORCPT ); Fri, 1 Apr 2011 20:10:39 -0400 Message-ID: <4D96695D.7020706@kernel.org> Date: Fri, 01 Apr 2011 17:10:05 -0700 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.14) Gecko/20110221 SUSE/3.1.8 Thunderbird/3.1.8 MIME-Version: 1.0 To: "H. Peter Anvin" 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> <4D9633E7.1010707@zytor.com> <4D9643F1.1090807@zytor.com> <4D9646C6.7060301@zytor.com> <4D965A08.2080203@kernel.org> <4D965BED.5000309@zytor.com> In-Reply-To: <4D965BED.5000309@zytor.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: acsmt357.oracle.com [141.146.40.157] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090201.4D96696E.0074,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1242 Lines: 34 On 04/01/2011 04:12 PM, H. Peter Anvin wrote: > On 04/01/2011 04:04 PM, Yinghai Lu wrote: >> On 04/01/2011 02:42 PM, H. Peter Anvin wrote: >>> >>> And why on Earth is it worth saving a couple of instructions (and >>> introducing code ugliness and a more complex testing matrix) in the case >>> when it is not? >> >> Please check this one, it moves storing mmu_cr4 to arch_prepare_suspend. >> > > You keep moving things around instead of answering the question. It > might be the right thing to do, but I would like an answer why, in your > opinion, the easy way isn't feasible. want to find right place to read back cr4 for hibernation/resume. it is one time using, so we could just read back one time at last and avoid touching it inset/clear_in_cr4. > > For suspend/resume, the right thing really is just to save CR4 like any > other processor register. not sure why mmu_cr4_features get overloaded. maybe power guys want to save one variable instead of using restore_rc4. Thanks Yinghai -- 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/