Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761408AbYGJTC2 (ORCPT ); Thu, 10 Jul 2008 15:02:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760181AbYGJTCG (ORCPT ); Thu, 10 Jul 2008 15:02:06 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:43591 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759640AbYGJTCD (ORCPT ); Thu, 10 Jul 2008 15:02:03 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: "Serge E. Hallyn" Cc: Dave Hansen , Oren Laadan , Kirill Korotaev , containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Nadia.Derbey@bull.net, Andrew Morton , nick@nick-andrew.net, Alexey Dobriyan References: <20080418054459.891481000@bull.net> <20080422193612.GA15835@martell.zuzino.mipt.ru> <1208890580.17117.14.camel@nimitz.home.sr71.net> <20080422210130.GA15937@martell.zuzino.mipt.ru> <1208904967.17117.51.camel@nimitz.home.sr71.net> <480ED9D5.1010906@parallels.com> <480FE037.2010302@cs.columbia.edu> <1215709949.9398.15.camel@nimitz> <20080710173246.GA1857@us.ibm.com> Date: Thu, 10 Jul 2008 11:55:34 -0700 In-Reply-To: <20080710173246.GA1857@us.ibm.com> (Serge E. Hallyn's message of "Thu, 10 Jul 2008 12:32:46 -0500") 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; sa04 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;"Serge E. Hallyn" X-Spam-Relay-Country: 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 * -0.2 BAYES_40 BODY: Bayesian spam probability is 20 to 40% * [score: 0.2616] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa04 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 XM_SPF_Neutral SPF-Neutral Subject: Re: Checkpoint/restart (was Re: [PATCH 0/4] - v2 - Object creation with a specified id) 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 Content-Length: 1481 Lines: 34 "Serge E. Hallyn" writes: >> So, the checkpoint-as-a-corefile idea sounds good to me, but it >> definitely leaves a lot of questions about exactly how we'll need to do >> the restore. > > Talking with Dave over irc, I kind of liked the idea of creating a new > fs/binfmt_cr.c that executes a checkpoint-as-a-coredump file. > > One thing I do not like about the checkpoint-as-coredump is that it begs > us to dump all memory out into the file. Our plan/hope was to save > ourselves from writing out most memory by: > > 1. associating a separate swapfile with each container > 2. doing a swapfile snapshot at each checkpoint > 3. dumping the pte entries (/proc/self/) > > If we do checkpoint-as-a-coredump, then we need userspace to coordinate > a kernel-generated coredump with a user-generated (?) swapfile snapshot. > But I guess we figure that out later. Well it is a matter of which VMAs you dump. For things that are file backed you need to dump them. I don't know that even a binfmt for per process level checkpoints is sufficient but I do know having something of that granularity looks much easier. Otherwise it takes a bazillian little syscalls to do things no one else is interested in doing. Eric -- 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/