From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932530AbbLVOq7 (ORCPT ); Tue, 22 Dec 2015 09:46:59 -0500 Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:48665 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932243AbbLVOq5 convert rfc822-to-8bit (ORCPT ); Tue, 22 Dec 2015 09:46:57 -0500 Date: Tue, 22 Dec 2015 15:46:49 +0100 From: Sebastian Andrzej Siewior To: Philipp Schrader Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, tglx@linutronix.de, paulmck@linux.vnet.ibm.com, rostedt@goodmis.org Subject: Re: [PATCH v3] tracing: Fix rcu splat from idle CPU on boot. Message-ID: <20151222144645.GA29103@breakpoint.cc> References: <1441397364-16883-1-git-send-email-philipp@peloton-tech.com> <20151214190709.GA19861@philipp-x250.peloton-tech.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <20151214190709.GA19861@philipp-x250.peloton-tech.com> 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 On 2015-12-14 11:07:09 [-0800], Philipp Schrader wrote: > With PREEMPT_RT and most of the lockdep-related options enabled I > encountered this splat when booting our DRA7 evaluation module: > > [ 0.055073] > [ 0.055076] =============================== > [ 0.055079] [ INFO: suspicious RCU usage. ] > [ 0.055084] 4.1.6+ #2 Not tainted > [ 0.055086] ------------------------------- > [ 0.055090] include/trace/events/hist.h:31 suspicious > rcu_dereference_check() usage! … > As per Steve Rotstedt's suggestion I changed the trace_* calls to > trace_*_rcuidle calls. He pointed out that the trace points were getting > triggered when rcu wasn't watching. > > Signed-off-by: Philipp Schrader > Acked-by: Paul E. McKenney I'm taking this for -RT. Is my assumption correct, that this goes into the v4.5 merge window once everybody is back from holidays? Sebastian