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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 DA536C433E0 for ; Thu, 21 May 2020 20:33:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F57220826 for ; Thu, 21 May 2020 20:33:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730611AbgEUUdx (ORCPT ); Thu, 21 May 2020 16:33:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729620AbgEUUbx (ORCPT ); Thu, 21 May 2020 16:31:53 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B8B2DC061A0E for ; Thu, 21 May 2020 13:31:53 -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 1jbrqj-0000Ru-B2; Thu, 21 May 2020 22:31:29 +0200 Received: from nanos.tec.linutronix.de (localhost [IPv6:::1]) by nanos.tec.linutronix.de (Postfix) with ESMTP id 4EE2F100606; Thu, 21 May 2020 22:31:28 +0200 (CEST) Message-Id: <20200521202117.962199649@linutronix.de> User-Agent: quilt/0.65 Date: Thu, 21 May 2020 22:05:25 +0200 From: Thomas Gleixner To: LKML Cc: Andy Lutomirski , Andrew Cooper , X86 ML , "Paul E. McKenney" , 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: [patch V9 12/39] x86/entry: Split out idtentry_exit_cond_resched() References: <20200521200513.656533920@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-transfer-encoding: 8-bit 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 The XEN PV hypercall requires the ability of conditional rescheduling when preemption is disabled because some hypercalls take ages. Split out the rescheduling code from idtentry_exit_cond_rcu() so it can be reused for that. Signed-off-by: Thomas Gleixner --- V9: New patch --- arch/x86/entry/common.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-) --- a/arch/x86/entry/common.c +++ b/arch/x86/entry/common.c @@ -580,6 +580,20 @@ bool noinstr idtentry_enter_cond_rcu(str return false; } +static void idtentry_exit_cond_resched(struct pt_regs *regs, bool may_sched) +{ + if (may_sched && !preempt_count()) { + /* Sanity check RCU and thread stack */ + rcu_irq_exit_check_preempt(); + if (IS_ENABLED(CONFIG_DEBUG_ENTRY)) + WARN_ON_ONCE(!on_thread_stack()); + if (need_resched()) + preempt_schedule_irq(); + } + /* Covers both tracing and lockdep */ + trace_hardirqs_on(); +} + /** * idtentry_exit_cond_rcu - Handle return from exception with conditional RCU * handling @@ -621,21 +635,7 @@ void noinstr idtentry_exit_cond_rcu(stru } instrumentation_begin(); - - /* Check kernel preemption, if enabled */ - if (IS_ENABLED(CONFIG_PREEMPTION)) { - if (!preempt_count()) { - /* Sanity check RCU and thread stack */ - rcu_irq_exit_check_preempt(); - if (IS_ENABLED(CONFIG_DEBUG_ENTRY)) - WARN_ON_ONCE(!on_thread_stack()); - if (need_resched()) - preempt_schedule_irq(); - } - } - /* Covers both tracing and lockdep */ - trace_hardirqs_on(); - + idtentry_exit_cond_resched(regs, IS_ENABLED(CONFIG_PREEMPTION)); instrumentation_end(); } else { /*