From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965281AbeEYJFw (ORCPT ); Fri, 25 May 2018 05:05:52 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:55003 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965197AbeEYJFo (ORCPT ); Fri, 25 May 2018 05:05:44 -0400 From: Anna-Maria Gleixner To: linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, bigeasy@linutronix.de, paulmck@linux.vnet.ibm.com, ebiederm@xmission.com, Anna-Maria Gleixner Subject: [PATCH v2 1/2] rcu: Update documentation of rcu_read_unlock() Date: Fri, 25 May 2018 11:05:06 +0200 Message-Id: <20180525090507.22248-2-anna-maria@linutronix.de> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20180525090507.22248-1-anna-maria@linutronix.de> References: <20180525090507.22248-1-anna-maria@linutronix.de> X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since commit b4abf91047cf ("rtmutex: Make wait_lock irq safe") the explanation in rcu_read_unlock() documentation about irq unsafe rtmutex wait_lock is no longer valid. Remove it to prevent kernel developers reading the documentation to rely on it. Suggested-by: Eric W. Biederman Signed-off-by: Anna-Maria Gleixner --- include/linux/rcupdate.h | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 36360d07f25b..64644fda3b22 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -653,9 +653,7 @@ static inline void rcu_read_lock(void) * Unfortunately, this function acquires the scheduler's runqueue and * priority-inheritance spinlocks. This means that deadlock could result * if the caller of rcu_read_unlock() already holds one of these locks or - * any lock that is ever acquired while holding them; or any lock which - * can be taken from interrupt context because rcu_boost()->rt_mutex_lock() - * does not disable irqs while taking ->wait_lock. + * any lock that is ever acquired while holding them. * * That said, RCU readers are never priority boosted unless they were * preempted. Therefore, one way to avoid deadlock is to make sure -- 2.15.1