From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932226Ab0G3Obx (ORCPT ); Fri, 30 Jul 2010 10:31:53 -0400 Received: from hera.kernel.org ([140.211.167.34]:39812 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756568Ab0G3Obv (ORCPT ); Fri, 30 Jul 2010 10:31:51 -0400 Message-ID: <4C52E22F.9060102@kernel.org> Date: Fri, 30 Jul 2010 16:31:11 +0200 From: Tejun Heo User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.7) Gecko/20100713 Thunderbird/3.1.1 MIME-Version: 1.0 To: Oleg Nesterov CC: "Michael S. Tsirkin" , Sridhar Samudrala , Peter Zijlstra , Ingo Molnar , netdev , lkml , "kvm@vger.kernel.org" , Andrew Morton , Dmitri Vorobiev , Jiri Kosina , Thomas Gleixner , Andi Kleen Subject: Re: [PATCH repost] sched: export sched_set/getaffinity to modules References: <20100701144624.GA11171@redhat.com> <4C2CABF2.2020801@kernel.org> <1277996135.1917.198.camel@laptop> <4C2E2987.9040702@us.ibm.com> <1278094270.1917.288.camel@laptop> <20100702210637.GA12433@redhat.com> <20100726171230.GA27644@redhat.com> <1280166688.3375.5.camel@localhost> <20100726180834.GA26988@redhat.com> <20100727154155.GA13419@redhat.com> <20100730141901.GA9076@redhat.com> In-Reply-To: <20100730141901.GA9076@redhat.com> 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, 30 Jul 2010 14:31:07 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On 07/30/2010 04:19 PM, Oleg Nesterov wrote: > But I must admit, I personally dislike this idea. A kernel thread which > is the child of the user-space process, and in fact it is not the "real" > kernel thread. I think this is against the common case. If you do not > care the signals/reparenting, why can't you fork the user-space process > which does all the work via ioctl's ? OK, I do not understand the problem > domain, probably this can't work. Having kernel threads which are children of user process is plain scary considering the many things parent/children relationship implies and various bugs and security vulnerabilities in the area. I can't pinpoint any problem but I think we really shouldn't be adding something like this for this specific use case. If we can get away with exporting a few symbols, let's go that way. Thanks. -- tejun