Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752187Ab0KSDyN (ORCPT ); Thu, 18 Nov 2010 22:54:13 -0500 Received: from adelie.canonical.com ([91.189.90.139]:56624 "EHLO adelie.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751345Ab0KSDyM (ORCPT ); Thu, 18 Nov 2010 22:54:12 -0500 Date: Thu, 18 Nov 2010 21:54:03 -0600 From: Serge Hallyn To: Tejun Heo Cc: Pavel Emelyanov , Kapil Arya , Gene Cooperman , "linux-kernel@vger.kernel.org" , "Eric W. Biederman" , Linux Containers Subject: Re: [Ksummit-2010-discuss] checkpoint-restart: naked patch Message-ID: <20101119035403.GA24031@hallyn.com> References: <20101106053204.GB12449@count0.beaverton.ibm.com> <20101106204008.GA31077@sundance.ccs.neu.edu> <4CD5D99A.8000402@cs.columbia.edu> <20101107184927.GF31077@sundance.ccs.neu.edu> <4CD72150.9070705@cs.columbia.edu> <4CE3C334.9080401@kernel.org> <20101117153902.GA1155@hallyn.com> <4CE3F8D1.10003@kernel.org> <4CE4EE21.6050305@parallels.com> <4CE4F672.1030904@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4CE4F672.1030904@kernel.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1014 Lines: 23 Quoting Tejun Heo (tj@kernel.org): > * And, most of all, there are userland implementation and > virtualization, making the benefit to overhead ratio completely off. > Userland implementation _already_ achieves most of what's necessary Guess I'll just be offensive here and say, straight-out: I don't believe it. Can I see the userspace implementation of c/r? If it's as good as the kernel level c/r, then aweseome - we don't need the kernel patches. If it's not as good, then the thing is, we're not drawing arbitrary lines saying "is this good enough", rather we want completely reliable and transparent c/r. IOW, the running task and the other end can't tell that a migration happened, and, if checkpoint says it worked, then restart must succeed. -serge -- 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/