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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 CBCCBC3F2D7 for ; Thu, 5 Mar 2020 08:11:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADE0B2146E for ; Thu, 5 Mar 2020 08:11:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726101AbgCEILx (ORCPT ); Thu, 5 Mar 2020 03:11:53 -0500 Received: from Galois.linutronix.de ([193.142.43.55]:49387 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725816AbgCEILx (ORCPT ); Thu, 5 Mar 2020 03:11:53 -0500 Received: from bigeasy by Galois.linutronix.de with local (Exim 4.80) (envelope-from ) id 1j9lbT-0000kj-Bb; Thu, 05 Mar 2020 09:11:35 +0100 Date: Thu, 5 Mar 2020 09:11:35 +0100 From: Sebastian Andrzej Siewior To: "Paul E. McKenney" Cc: josh@joshtriplett.org, rostedt@goodmis.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, joel@joelfernandes.org, tglx@linutronix.de, swood@redhat.com, williams@redhat.com, juri.lelli@redhat.com, linux-rt-users@vger.kernel.org, rcu@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@kernel.org Subject: Re: RCU use of swait Message-ID: <20200305081135.yg7wryd3hrqzocrm@linutronix.de> References: <20200305003526.GA20601@paulmck-ThinkPad-P72> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200305003526.GA20601@paulmck-ThinkPad-P72> Sender: rcu-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org On 2020-03-04 16:35:26 [-0800], Paul E. McKenney wrote: > Hello! Hi Paul, > Or is there some other reason why {S,}RCU needs to use swait that I > am forgetting? swait can be used in hardirq-context (on RT) that is in a section within local_irq_save() / raw_spin_lock() and so. wait on the hand uses spinlock_t which can not be used in this context. So if you have no users which fall into that category then you could move back to wait.h. > Thanx, Paul Sebastian