From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755070AbcBZUXV (ORCPT ); Fri, 26 Feb 2016 15:23:21 -0500 Received: from mail-pf0-f170.google.com ([209.85.192.170]:33971 "EHLO mail-pf0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754856AbcBZUXU (ORCPT ); Fri, 26 Feb 2016 15:23:20 -0500 Subject: Re: [RFC PATCH] kernfs: create raw version kernfs_path_len and kernfs_path To: Steven Rostedt References: <1456510505-6620-1-git-send-email-yang.shi@linaro.org> <20160226135628.09ce727c@gandalf.local.home> <56D0A97E.90706@linaro.org> <56D0AEAC.3070002@linaro.org> <20160226151503.39d39e45@gandalf.local.home> Cc: gregkh@linuxfoundation.org, tj@kernel.org, lizefan@huawei.com, tglx@linutronix.de, bigeasy@linutronix.de, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, linaro-kernel@lists.linaro.org From: "Shi, Yang" Message-ID: <56D0B435.4080309@linaro.org> Date: Fri, 26 Feb 2016 12:23:17 -0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20160226151503.39d39e45@gandalf.local.home> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/26/2016 12:15 PM, Steven Rostedt wrote: > On Fri, 26 Feb 2016 11:59:40 -0800 > "Shi, Yang" wrote: > > >> BTW, it sounds this is not the only point where kernfs_node could be >> updated, __kernfs_remove should need synchronize_sched too. >> > > Question is, can the kernfs of a cgroup be removed while the cgroup is > still active? Hmm, it sounds unlikely to me. Yang > > I don't see the kernfs_rename_lock being held anywhere in that > remove. If it can be an issue there with this patch, then it's an issue > today, because the kernfs_mutex is not held by the tracepoint. > > -- Steve >