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=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT 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 EADB0C43381 for ; Thu, 21 Mar 2019 20:59:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C318F2190A for ; Thu, 21 Mar 2019 20:59:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727434AbfCUU7m (ORCPT ); Thu, 21 Mar 2019 16:59:42 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:39520 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727393AbfCUU7j (ORCPT ); Thu, 21 Mar 2019 16:59:39 -0400 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1h74ml-0005nK-Py; Thu, 21 Mar 2019 21:59:36 +0100 Date: Thu, 21 Mar 2019 21:59:35 +0100 From: Sebastian Andrzej Siewior To: linux-kernel@vger.kernel.org Cc: Tejun Heo , Lai Jiangshan , Ingo Molnar , Peter Zijlstra , Thomas Gleixner Subject: Re: [PATCH 1/2] workqueue: Use normal rcu Message-ID: <20190321205935.7ndo5k5zumc77h37@linutronix.de> References: <20190313165548.19713-1-bigeasy@linutronix.de> <20190313165548.19713-2-bigeasy@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190313165548.19713-2-bigeasy@linutronix.de> User-Agent: NeoMutt/20180716 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019-03-13 17:55:47 [+0100], To linux-kernel@vger.kernel.org wrote: > From: Thomas Gleixner > > There is no need for sched_rcu. The undocumented reason why sched_rcu > is used is to avoid a few explicit rcu_read_lock()/unlock() pairs by > the fact that sched_rcu reader side critical sections are also protected > by preempt or irq disabled regions. > > Replace rcu_read_lock_sched with rcu_read_lock and acquire the RCU lock > where it is not yet explicit acquired. Replace local_irq_disable() with > rcu_read_lock(). Update asserts. > > Signed-off-by: Thomas Gleixner > [bigeasy: mangle changelog a little] > Signed-off-by: Sebastian Andrzej Siewior A gentle ping. Sebastian