Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754438Ab0KSQvP (ORCPT ); Fri, 19 Nov 2010 11:51:15 -0500 Received: from hera.kernel.org ([140.211.167.34]:51965 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753892Ab0KSQvO (ORCPT ); Fri, 19 Nov 2010 11:51:14 -0500 Message-ID: <4CE6AAB9.3070009@kernel.org> Date: Fri, 19 Nov 2010 17:50:01 +0100 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.12) Gecko/20101027 Lightning/1.0b2 Thunderbird/3.1.6 MIME-Version: 1.0 To: Alexey Dobriyan CC: Kirill Korotaev , Serge Hallyn , Kapil Arya , Gene Cooperman , "linux-kernel@vger.kernel.org" , Pavel Emelianov , "Eric W. Biederman" , Linux Containers Subject: Re: [Ksummit-2010-discuss] checkpoint-restart: naked patch References: <20101104164401.GC10656@sundance.ccs.neu.edu> <4CD3CE29.2010105@kernel.org> <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> <20101119041045.GC24031@hallyn.com> <4CE683E1.6010500@kernel.org> <04F4899E-B5C7-4BAF-8F2F-05D507A91408@parallels.com> <4CE698C5.5060806@kernel.org> <4CE6A076.2020807@kernel.org> <4CE6A397.6010105@kernel.org> <4CE6A69F.4030008@kernel.org> In-Reply-To: X-Enigmail-Version: 1.1.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Fri, 19 Nov 2010 16:50:03 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1769 Lines: 43 On 11/19/2010 05:38 PM, Alexey Dobriyan wrote: > On Fri, Nov 19, 2010 at 6:32 PM, Tejun Heo wrote: >> On 11/19/2010 05:27 PM, Alexey Dobriyan wrote: >>> On Fri, Nov 19, 2010 at 6:19 PM, Tejun Heo wrote: >>>>> The paragon of absurdity is struct task_struct::did_exec . >>>> >>>> Yeah, then go and figure how to do that in a way which would be useful >>>> for other purposes too instead of trying to shove the whole >>>> checkpointer inside the kernel. It sure would be harder but hey >>>> that's the way it is. >>> >>> System call for one bit? This is ridiculous. >> >> Why not just a flag in proc entry? It's a frigging single bit. > > Because /proc/*/did_exec useless to anyone but C/R (even for reading!). I don't think you'll need a full file. Just shove it in status or somewhere. Your argument is completely absurd. So, because exporting single bit is so horrible to everyone else, you want to shove the whole frigging checkpointer inside the kernel? > Because code is much simpler: > > tsk->did_exec = !!tsk_img->did_exec; > + > __u8 did_exec; Sigh, yeah, except for the horror show to create tsk_img. Your "paragon of absurdity" is did_exec which is only ever used to decide whether setpgid() should fail with -EACCES, seriously? Here's a thought. Ignore it for now and concentrate on more relevant problems. I'm fairly sure CR'd program malfunctioning over did_exec wouldn't mark the beginning of the end of our civilization. You gotta be kidding me. -- tejun -- 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/