Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752051AbcCDMwa (ORCPT ); Fri, 4 Mar 2016 07:52:30 -0500 Received: from mail-yw0-f174.google.com ([209.85.161.174]:33017 "EHLO mail-yw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751216AbcCDMw0 (ORCPT ); Fri, 4 Mar 2016 07:52:26 -0500 Date: Fri, 4 Mar 2016 07:52:24 -0500 From: Tejun Heo To: Yang Shi Cc: gregkh@linuxfoundation.org, lizefan@huawei.com, tglx@linutronix.de, rostedt@goodmis.org, bigeasy@linutronix.de, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, linaro-kernel@lists.linaro.org Subject: Re: [RFC V4 PATCH] trace: writeback: replace cgroup path to cgroup ino Message-ID: <20160304125224.GG13868@htj.duckdns.org> References: <1456996137-8354-1-git-send-email-yang.shi@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1456996137-8354-1-git-send-email-yang.shi@linaro.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 486 Lines: 13 On Thu, Mar 03, 2016 at 01:08:57AM -0800, Yang Shi wrote: > commit 5634cc2aa9aebc77bc862992e7805469dcf83dac ("writeback: update writeback > tracepoints to report cgroup") made writeback tracepoints print out cgroup > path when CGROUP_WRITEBACK is enabled, but it may trigger the below bug on -rt > kernel since kernfs_path and kernfs_path_len are called by tracepoints, which > acquire spin lock that is sleepable on -rt kernel. Acked-by: Tejun Heo Thanks. -- tejun