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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_GIT 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 8E08DC28CC0 for ; Wed, 29 May 2019 20:37:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 664BC24177 for ; Wed, 29 May 2019 20:37:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=digitalocean.com header.i=@digitalocean.com header.b="fuh0Wd+F" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726192AbfE2UhC (ORCPT ); Wed, 29 May 2019 16:37:02 -0400 Received: from mail-it1-f195.google.com ([209.85.166.195]:55794 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726605AbfE2Ug7 (ORCPT ); Wed, 29 May 2019 16:36:59 -0400 Received: by mail-it1-f195.google.com with SMTP id g24so6235390iti.5 for ; Wed, 29 May 2019 13:36:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=digitalocean.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :in-reply-to:references; bh=i9u6VHWW3afjnCOMoNc95nC4T3wZam37RatzS70qNxg=; b=fuh0Wd+FcHdwZa+R9oeIqWNDEtcL99azHHKi53RKIewMK6Ac98II3TJHHrwiYLJuYn PV4RpKg0GW0j7iW9tcob4LXKlgsZMsJ7eqGeWgZA9BOcvp5s9aRTKUiV3vtZFRmALokf MCg/glaIwQgO4UGF7UWSeSUGtrRtJmJ4pSxQc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=i9u6VHWW3afjnCOMoNc95nC4T3wZam37RatzS70qNxg=; b=tOqoWyRdDIuTDeRzhOHk0QE8sm35kzdLWi90cgE8+pXIjMK6YtouKMmsds+hAxS5Le M2sNbGt3xnVjh1N+nwJejU62ydQUv6rxsohT6J3WfaxLlh+kCYBPW9QDBF+hWeKULQjf wGl5pfu9CBAZD1qQapYvbBe276ZnPDn6yWim9nGYd9WAKvE2sJRPtrMJwkI/T25sPJ1Q 2cnOEkdThuDwTgn1bgS4FY3xBB+lAkKk4muW0qnllAkzqvfo73jlDWmadqpQAjCARc4y qfPu7kwHRgJJ8NKI10iz+/OHz/rq14C3OwZEoDrkvHK2QIII5m6DCb+a/uIfccT0VJ7e WRYQ== X-Gm-Message-State: APjAAAWFnJieISlRic7e5S8mw80r7uw7q6HDkkCq5+t2kLemZP8k17pM QTefsFcqeH4BcceesQZguF4+Fg== X-Google-Smtp-Source: APXvYqzBPnidyGrEle1CnwytGLYUAa8ffokB1gphgArlufGGIrqmzILTn4aW7KVObRObI9LQxXIOtQ== X-Received: by 2002:a02:a806:: with SMTP id f6mr1470858jaj.74.1559162218281; Wed, 29 May 2019 13:36:58 -0700 (PDT) Received: from swap-tester ([178.128.225.14]) by smtp.gmail.com with ESMTPSA id s2sm181921ioj.8.2019.05.29.13.36.57 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 29 May 2019 13:36:57 -0700 (PDT) From: Vineeth Remanan Pillai To: Nishanth Aravamudan , Julien Desfossez , Peter Zijlstra , Tim Chen , mingo@kernel.org, tglx@linutronix.de, pjt@google.com, torvalds@linux-foundation.org Cc: linux-kernel@vger.kernel.org, subhra.mazumdar@oracle.com, fweisbec@gmail.com, keescook@chromium.org, kerrnel@google.com, Phil Auld , Aaron Lu , Aubrey Li , Valentin Schneider , Mel Gorman , Pawan Gupta , Paolo Bonzini Subject: [RFC PATCH v3 01/16] stop_machine: Fix stop_cpus_in_progress ordering Date: Wed, 29 May 2019 20:36:37 +0000 Message-Id: <0fd8fd4b99b9b9aa88d8b2dff897f7fd0d88f72c.1559129225.git.vpillai@digitalocean.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Zijlstra Make sure the entire for loop has stop_cpus_in_progress set. Signed-off-by: Peter Zijlstra (Intel) --- kernel/stop_machine.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 067cb83f37ea..583119e0c51c 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -375,6 +375,7 @@ static bool queue_stop_cpus_work(const struct cpumask *cpumask, */ preempt_disable(); stop_cpus_in_progress = true; + barrier(); for_each_cpu(cpu, cpumask) { work = &per_cpu(cpu_stopper.stop_work, cpu); work->fn = fn; @@ -383,6 +384,7 @@ static bool queue_stop_cpus_work(const struct cpumask *cpumask, if (cpu_stop_queue_work(cpu, work)) queued = true; } + barrier(); stop_cpus_in_progress = false; preempt_enable(); -- 2.17.1