From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1147C433E0 for ; Wed, 6 Jan 2021 16:53:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69C2522EBD for ; Wed, 6 Jan 2021 16:53:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727334AbhAFQxO (ORCPT ); Wed, 6 Jan 2021 11:53:14 -0500 Received: from mail.kernel.org ([198.145.29.99]:55754 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727012AbhAFQxO (ORCPT ); Wed, 6 Jan 2021 11:53:14 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 81EF82313F; Wed, 6 Jan 2021 16:52:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1609951953; bh=cXheTuQ4x1aiyI69dvp9kCvnCfE+d3M6Gi4mDOGKAYg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tr3rjLJ69xl7infr3kjvFl3fOtwe/EHvKkaQKpAmy8eO1tOlbAPXvm9QC/ED/Thif NUvTl2BQF4Ont9BFbOgjjFfGbR/EHy9jAEu+PCt062FhFIEAzpWH027vWu35lEbz0+ Kyt9M67i6fhxk1+M2bN4H4VP0o3H5gb+SOA4tP1XARLv7yGWx3Mvk64iBwg6lf/B6s xg7EJX3hQ7gHXy9D4MDtjdLn+x5Q40dyN68KUZfLwK45jmV9AoQAQ1zengATEOJd27 IvkU0ps2owZFbnF9P7ZZNORs5hLdBc9IVyNrr1Orel4acmUcxXtDfVFfFe4u5eoWJQ Xu/lj4KYxp06g== From: paulmck@kernel.org To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 1/4] rcu: Mark obtuse portion of stall warning as internal debug Date: Wed, 6 Jan 2021 08:52:28 -0800 Message-Id: <20210106165231.20441-1-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20210106165210.GA20296@paulmck-ThinkPad-P72> References: <20210106165210.GA20296@paulmck-ThinkPad-P72> Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: "Paul E. McKenney" There is a rather obtuse string that can be printed as part of an expedited RCU CPU stall-warning message that starts with "blocking rcu_node structures". Under normal conditions, most of this message is just repeating the list of CPUs blocking the current expedited grace period, but in a manner that is rather difficult to read. This commit therefore marks this message as "(internal RCU debug)" in an effort to give people the option of avoiding wasting time attempting to extract nonexistent additional meaning from this portion of the message. Reported-by: Jonathan Lemon Signed-off-by: Paul E. McKenney --- kernel/rcu/tree_exp.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h index 8760b6e..6c6ff06 100644 --- a/kernel/rcu/tree_exp.h +++ b/kernel/rcu/tree_exp.h @@ -545,7 +545,7 @@ static void synchronize_rcu_expedited_wait(void) data_race(rnp_root->expmask), ".T"[!!data_race(rnp_root->exp_tasks)]); if (ndetected) { - pr_err("blocking rcu_node structures:"); + pr_err("blocking rcu_node structures (internal RCU debug):"); rcu_for_each_node_breadth_first(rnp) { if (rnp == rnp_root) continue; /* printed unconditionally */ -- 2.9.5