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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 46BE3C35666 for ; Fri, 21 Feb 2020 21:26:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 19C1A24650 for ; Fri, 21 Feb 2020 21:26:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582320386; bh=au/cT7hvKSj34WqOFe/k9PkkTiQcR9jMkSiGWA8g5os=; h=From:To:Subject:Date:In-Reply-To:References:In-Reply-To: References:List-ID:From; b=esB1xDXi7391sR53HSH7srMlMo4AJUGmznqeZHDe0B+zTJqxSun63StOO5ORPHKva Jm4BovPLX6eUtvAxLI8Ea/Xe+nEM+yzZhQbSt10MHSwwBFv+bkSkgOuUmg/FpYMs95 i7WoHBa1RqbZ6GyGDujn/wxZoqYXeO0zmsMMN004= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729819AbgBUV0U (ORCPT ); Fri, 21 Feb 2020 16:26:20 -0500 Received: from mail.kernel.org ([198.145.29.99]:39274 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729372AbgBUVZa (ORCPT ); Fri, 21 Feb 2020 16:25:30 -0500 Received: from localhost.localdomain (c-98-220-238-81.hsd1.il.comcast.net [98.220.238.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 328172467D; Fri, 21 Feb 2020 21:25:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582320329; bh=au/cT7hvKSj34WqOFe/k9PkkTiQcR9jMkSiGWA8g5os=; h=From:To:Subject:Date:In-Reply-To:References:In-Reply-To: References:From; b=irwuujBHy7VjxeWOlXyIw9F4m/13iVJ0Qkpf1CM0Li7+wGqgC94hEvC23gfl2O82Q JdAZrQp30G81pOYFMKhWm8uljCjGrePkZgFOU3a1WqO9GHuLx1JZz33KrS+/7wmqLk AZCcS/hSk2C5yGJ1ZMZ4PKPbnrrWI8465PsFXuKI= From: zanussi@kernel.org To: LKML , linux-rt-users , Steven Rostedt , Thomas Gleixner , Carsten Emde , John Kacur , Sebastian Andrzej Siewior , Daniel Wagner , Tom Zanussi Subject: [PATCH RT 15/25] sched: migrate_enable: Use select_fallback_rq() Date: Fri, 21 Feb 2020 15:24:43 -0600 Message-Id: X-Mailer: git-send-email 2.14.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-rt-users-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rt-users@vger.kernel.org From: Scott Wood v4.14.170-rt75-rc1 stable review patch. If anyone has any objections, please let me know. ----------- [ Upstream commit adfa969d4cfcc995a9d866020124e50f1827d2d1 ] migrate_enable() currently open-codes a variant of select_fallback_rq(). However, it does not have the "No more Mr. Nice Guy" fallback and thus it will pass an invalid CPU to the migration thread if cpus_mask only contains a CPU that is !active. Signed-off-by: Scott Wood Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Tom Zanussi --- kernel/sched/core.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 189e6f08575e..46324d2099e3 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7008,6 +7008,7 @@ void migrate_enable(void) if (p->migrate_disable_update) { struct rq *rq; struct rq_flags rf; + int cpu = task_cpu(p); rq = task_rq_lock(p, &rf); update_rq_clock(rq); @@ -7017,21 +7018,15 @@ void migrate_enable(void) p->migrate_disable_update = 0; - WARN_ON(smp_processor_id() != task_cpu(p)); - if (!cpumask_test_cpu(task_cpu(p), &p->cpus_mask)) { - const struct cpumask *cpu_valid_mask = cpu_active_mask; - struct migration_arg arg; - unsigned int dest_cpu; - - if (p->flags & PF_KTHREAD) { - /* - * Kernel threads are allowed on online && !active CPUs - */ - cpu_valid_mask = cpu_online_mask; - } - dest_cpu = cpumask_any_and(cpu_valid_mask, &p->cpus_mask); - arg.task = p; - arg.dest_cpu = dest_cpu; + WARN_ON(smp_processor_id() != cpu); + if (!cpumask_test_cpu(cpu, &p->cpus_mask)) { + struct migration_arg arg = { p }; + struct rq_flags rf; + + rq = task_rq_lock(p, &rf); + update_rq_clock(rq); + arg.dest_cpu = select_fallback_rq(cpu, p); + task_rq_unlock(rq, p, &rf); unpin_current_cpu(); preempt_lazy_enable(); -- 2.14.1