From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752188AbcJJMxZ (ORCPT ); Mon, 10 Oct 2016 08:53:25 -0400 Received: from mail-io0-f194.google.com ([209.85.223.194]:34208 "EHLO mail-io0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752101AbcJJMxX (ORCPT ); Mon, 10 Oct 2016 08:53:23 -0400 Date: Mon, 10 Oct 2016 08:53:03 -0400 From: Tejun Heo To: Balbir Singh Cc: Michael Ellerman , torvalds@linux-foundation.org, linuxppc-dev@lists.ozlabs.org, akpm@linux-foundation.org, kernel-team@fb.com, jiangshanlai@gmail.com, linux-kernel@vger.kernel.org Subject: Re: Oops on Power8 (was Re: [PATCH v2 1/7] workqueue: make workqueue available early during boot) Message-ID: <20161010125303.GA29742@mtj.duckdns.org> References: <1473967821-24363-1-git-send-email-tj@kernel.org> <1473967821-24363-2-git-send-email-tj@kernel.org> <20160917172314.GB10771@mtj.duckdns.org> <87twck5wqo.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.7.0 (2016-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 10, 2016 at 10:17:16PM +1100, Balbir Singh wrote: > rest_init() > { > ... > kernel_thread(kernel_init, NULL, CLONE_FS); > numa_default_policy(); > pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES); > rcu_read_lock(); > kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns); > ... > > } > > create_worker() needs kthreadd, it wakes up kthreadd in kthread_create_on_node, > workqueue_init() is called from kernel_init() , but kthreadd is created after > the call to kernel_init(), so its touch and go But the first thing kernel_init_freeable() does is wait_for_completion(&kthreadd_done). Thanks. -- tejun