From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754820AbYEPDBP (ORCPT ); Thu, 15 May 2008 23:01:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757730AbYEPDAp (ORCPT ); Thu, 15 May 2008 23:00:45 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:45808 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756209AbYEPDAS (ORCPT ); Thu, 15 May 2008 23:00:18 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: "Huang, Ying" Cc: Vivek Goyal , Pavel Machek , nigel@nigel.suspend2.net, "Rafael J. Wysocki" , Andrew Morton , linux-kernel@vger.kernel.org, Kexec Mailing List References: <1210574441.30365.8.camel@caritas-dev.intel.com> <20080513053408.GA5870@redhat.com> <1210730266.23707.50.camel@caritas-dev.intel.com> <20080514025607.GA19944@redhat.com> <1210736275.23707.62.camel@caritas-dev.intel.com> <1210827473.23707.133.camel@caritas-dev.intel.com> <20080516020043.GC6926@redhat.com> <1210904374.23707.178.camel@caritas-dev.intel.com> Date: Thu, 15 May 2008 19:55:44 -0700 In-Reply-To: <1210904374.23707.178.camel@caritas-dev.intel.com> (Ying Huang's message of "Fri, 16 May 2008 10:19:34 +0800") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SA-Exim-Connect-IP: 24.130.11.59 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-DCC: XMission; sa03 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;"Huang, Ying" X-Spam-Report: * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -1.1 BAYES_05 BODY: Bayesian spam probability is 1 to 5% * [score: 0.0107] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa03 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 XM_SPF_Neutral SPF-Neutral Subject: Re: [PATCH] kexec based hibernation: a prototype of kexec multi-stage load X-SA-Exim-Version: 4.2 (built Thu, 03 Mar 2005 10:44:12 +0100) X-SA-Exim-Scanned: Yes (on mgr1.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "Huang, Ying" writes: > The disadvantage of this solution is that kernel B must know it is > original kernel (A) or kexeced kernel (B). Different code should be used > by kernel A and kernel B. And after jump from A to B, jump from B to A, > when jump from A to B again, kernel A must use different code from the > first time. I don't know what the case is for keeping two kernels in memory and switching between them. I suspect a small piece of trampoline code between the two kernels could handle the case. (i.e. purgatory pays attention). That is a fundamental aspect of the design. A general purpose infrastructure with trampoline code to adapt it to whatever situation comes up. Eric