Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757757Ab0GBVJH (ORCPT ); Fri, 2 Jul 2010 17:09:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:28174 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751470Ab0GBVJF (ORCPT ); Fri, 2 Jul 2010 17:09:05 -0400 Date: Fri, 2 Jul 2010 23:06:37 +0200 From: Oleg Nesterov To: Peter Zijlstra Cc: Sridhar Samudrala , Tejun Heo , "Michael S. Tsirkin" , 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 Message-ID: <20100702210637.GA12433@redhat.com> References: <1277988395.1917.47.camel@laptop> <20100701130816.GB32223@redhat.com> <1277991024.1917.108.camel@laptop> <20100701133956.GD32223@redhat.com> <4C2CA5C5.4040402@kernel.org> <20100701144624.GA11171@redhat.com> <4C2CABF2.2020801@kernel.org> <1277996135.1917.198.camel@laptop> <4C2E2987.9040702@us.ibm.com> <1278094270.1917.288.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1278094270.1917.288.camel@laptop> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1170 Lines: 31 On 07/02, Peter Zijlstra wrote: > > On Fri, 2010-07-02 at 11:01 -0700, Sridhar Samudrala wrote: > > > > Does it (Tejun's kthread_clone() patch) also inherit the > > cgroup of the caller? > > Of course, its a simple do_fork() which inherits everything just as you > would expect from a similar sys_clone()/sys_fork() call. Yes. And I'm afraid it can inherit more than we want. IIUC, this is called from ioctl(), right? Then the new thread becomes the natural child of the caller, and it shares ->mm with the parent. And files, dup_fd() without CLONE_FS. Signals. Say, if you send SIGKILL to this new thread, it can't sleep in TASK_INTERRUPTIBLE or KILLABLE after that. And this SIGKILL can be sent just because the parent gets SIGQUIT or abother coredumpable signal. Or the new thread can recieve SIGSTOP via ^Z. Perhaps this is OK, I do not know. Just to remind that kernel_thread() is merely clone(CLONE_VM). Oleg. -- 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/