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=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 2CA61C4360C for ; Fri, 27 Sep 2019 08:11:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A3872146E for ; Fri, 27 Sep 2019 08:11:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727040AbfI0ILK (ORCPT ); Fri, 27 Sep 2019 04:11:10 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:45281 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726925AbfI0ILE (ORCPT ); Fri, 27 Sep 2019 04:11:04 -0400 Received: from [5.158.153.53] (helo=tip-bot2.lab.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iDlKz-0005cv-63; Fri, 27 Sep 2019 10:10:49 +0200 Received: from [127.0.1.1] (localhost [IPv6:::1]) by tip-bot2.lab.linutronix.de (Postfix) with ESMTP id D49251C0440; Fri, 27 Sep 2019 10:10:43 +0200 (CEST) Date: Fri, 27 Sep 2019 08:10:43 -0000 From: "tip-bot2 for Mathieu Desnoyers" Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/urgent] sched/membarrier: Remove redundant check Cc: Oleg Nesterov , Mathieu Desnoyers , "Peter Zijlstra (Intel)" , Chris Metcalf , Christoph Lameter , "Eric W. Biederman" , Kirill Tkhai , Linus Torvalds , Mike Galbraith , "Paul E. McKenney" , "Russell King - ARM Linux admin" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , linux-kernel@vger.kernel.org In-Reply-To: <20190919173705.2181-3-mathieu.desnoyers@efficios.com> References: <20190919173705.2181-3-mathieu.desnoyers@efficios.com> MIME-Version: 1.0 Message-ID: <156957184378.9866.15796834930588841787.tip-bot2@tip-bot2> X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit 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 following commit has been merged into the sched/urgent branch of tip: Commit-ID: 09554009c0cad4cb2223dd943c813c9257c6883a Gitweb: https://git.kernel.org/tip/09554009c0cad4cb2223dd943c813c9257c6883a Author: Mathieu Desnoyers AuthorDate: Thu, 19 Sep 2019 13:37:00 -04:00 Committer: Ingo Molnar CommitterDate: Wed, 25 Sep 2019 17:42:30 +02:00 sched/membarrier: Remove redundant check Checking that the number of threads is 1 is redundant with checking mm_users == 1. No change in functionality intended. Suggested-by: Oleg Nesterov Signed-off-by: Mathieu Desnoyers Signed-off-by: Peter Zijlstra (Intel) Cc: Chris Metcalf Cc: Christoph Lameter Cc: Eric W. Biederman Cc: Kirill Tkhai Cc: Linus Torvalds Cc: Mike Galbraith Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Russell King - ARM Linux admin Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20190919173705.2181-3-mathieu.desnoyers@efficios.com Signed-off-by: Ingo Molnar --- kernel/sched/membarrier.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c index d48b95f..7ccbd0e 100644 --- a/kernel/sched/membarrier.c +++ b/kernel/sched/membarrier.c @@ -186,7 +186,7 @@ static int membarrier_register_global_expedited(void) MEMBARRIER_STATE_GLOBAL_EXPEDITED_READY) return 0; atomic_or(MEMBARRIER_STATE_GLOBAL_EXPEDITED, &mm->membarrier_state); - if (atomic_read(&mm->mm_users) == 1 && get_nr_threads(p) == 1) { + if (atomic_read(&mm->mm_users) == 1) { /* * For single mm user, single threaded process, we can * simply issue a memory barrier after setting @@ -232,7 +232,7 @@ static int membarrier_register_private_expedited(int flags) if (flags & MEMBARRIER_FLAG_SYNC_CORE) atomic_or(MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE, &mm->membarrier_state); - if (!(atomic_read(&mm->mm_users) == 1 && get_nr_threads(p) == 1)) { + if (atomic_read(&mm->mm_users) != 1) { /* * Ensure all future scheduler executions will observe the * new thread flag state for this process.