Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754583Ab0KSQz6 (ORCPT ); Fri, 19 Nov 2010 11:55:58 -0500 Received: from mail-ew0-f46.google.com ([209.85.215.46]:47296 "EHLO mail-ew0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754194Ab0KSQz5 convert rfc822-to-8bit (ORCPT ); Fri, 19 Nov 2010 11:55:57 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=Dox4TxEgpaIgxf6sxQuEWmtaynCnz6Xzuj6HOmvBgk5IOV7yPKlqXkF8lihxttOvrh hVWnLvPbL/+3W10vsHKMCX0E3j/+sEFjfOCy0xDl/lWipuiXvRojIBdAqMS6cGSLew+B s38h+pbplQ0A6UAM/gS1HAZWUHsJh89e3yRXM= MIME-Version: 1.0 In-Reply-To: <4CE6AAB9.3070009@kernel.org> 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> <4CE6AAB9.3070009@kernel.org> Date: Fri, 19 Nov 2010 18:55:55 +0200 Message-ID: Subject: Re: [Ksummit-2010-discuss] checkpoint-restart: naked patch From: Alexey Dobriyan To: Tejun Heo Cc: Kirill Korotaev , Serge Hallyn , Kapil Arya , Gene Cooperman , "linux-kernel@vger.kernel.org" , Pavel Emelianov , "Eric W. Biederman" , Linux Containers Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1878 Lines: 46 On Fri, Nov 19, 2010 at 6:50 PM, Tejun Heo wrote: > 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. task_struct image work is common for both userspace C/R and in-kernel. You _have_ to define it. Simpler code is only first line. > 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. You're so newjerseyly now. -- 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/