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 B1385C433DF for ; Thu, 21 May 2020 08:31:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8B1D62070A for ; Thu, 21 May 2020 08:31:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728685AbgEUIbo (ORCPT ); Thu, 21 May 2020 04:31:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728538AbgEUIbo (ORCPT ); Thu, 21 May 2020 04:31:44 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6F5AEC061A0E for ; Thu, 21 May 2020 01:31:44 -0700 (PDT) Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jbgbf-0004xZ-OY; Thu, 21 May 2020 10:31:11 +0200 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id 204E0100C2D; Thu, 21 May 2020 10:31:11 +0200 (CEST) From: Thomas Gleixner To: paulmck@kernel.org Cc: Andy Lutomirski , LKML , X86 ML , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon , Tom Lendacky , Wei Liu , Michael Kelley , Jason Chen CJ , Zhao Yakui , "Peter Zijlstra \(Intel\)" Subject: Re: [patch V6 12/37] x86/entry: Provide idtentry_entry/exit_cond_rcu() In-Reply-To: <20200520232550.GA20812@paulmck-ThinkPad-P72> References: <87a7237k3x.fsf@nanos.tec.linutronix.de> <874ksb7hbg.fsf@nanos.tec.linutronix.de> <20200520022353.GN2869@paulmck-ThinkPad-P72> <20200520180546.GQ2869@paulmck-ThinkPad-P72> <87o8qiv135.fsf@nanos.tec.linutronix.de> <20200520221531.GW2869@paulmck-ThinkPad-P72> <20200520232550.GA20812@paulmck-ThinkPad-P72> Date: Thu, 21 May 2020 10:31:11 +0200 Message-ID: <87zha1u1tc.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "Paul E. McKenney" writes: > On Wed, May 20, 2020 at 03:15:31PM -0700, Paul E. McKenney wrote: > Same patch, but with updated commit log based on IRC discussion > with Andy. Fun. I came up with the same thing before going to bed. Just that I named the function differently: rcu_irq_enter_check_tick() > #if defined(CONFIG_TINY_RCU) > > +static inline void tickle_nohz_for_rcu(void) > +{ > +} > + > static inline void rcu_nmi_enter(void) > { > } > @@ -23,6 +27,7 @@ static inline void rcu_nmi_exit(void) > } > > #else > +extern void tickle_nohz_for_rcu(void); And I made this a NOP for for !NOHZ_FULL systems and avoided the call if context tracking is not enabled at boot. void __rcu_irq_enter_check_tick(void); static inline void rcu_irq_enter_check_tick(void) { if (context_tracking_enabled()) __rcu_irq_enter_check_tick(); } Thanks, tglx