From nobody Fri Dec 19 16:00:56 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 882A9C38A2D for ; Mon, 24 Oct 2022 16:27:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229964AbiJXQ1F (ORCPT ); Mon, 24 Oct 2022 12:27:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50716 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233295AbiJXQ0b (ORCPT ); Mon, 24 Oct 2022 12:26:31 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5740C2C126; Mon, 24 Oct 2022 08:13:13 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 744EB612B7; Mon, 24 Oct 2022 12:49:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 82573C433C1; Mon, 24 Oct 2022 12:49:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666615779; bh=7ejy0d+KKwbbxyY1c34JDvM+tldrF2f56p9tbQ3YmFw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XmUhT+/ySQPeu+d+vOCQRb6f65yy7x+RjxTeEa93+Jvo6DSnGaiM8k3QXylBMvIxa jjkYg6sDVPdKXglP4br1yIRHZRY23NT94uKtEO7vTzjNADDt4SJ9SHGIeTD5BUMZ1T HJnD6EpcO9mLGJxLcJdUmfIeFYchrFMRNehJRUWQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Waiman Long , Tejun Heo , Sasha Levin Subject: [PATCH 5.15 380/530] cgroup/cpuset: Enable update_tasks_cpumask() on top_cpuset Date: Mon, 24 Oct 2022 13:32:04 +0200 Message-Id: <20221024113102.248576394@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024113044.976326639@linuxfoundation.org> References: <20221024113044.976326639@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Waiman Long [ Upstream commit ec5fbdfb99d18482619ac42605cb80fbb56068ee ] Previously, update_tasks_cpumask() is not supposed to be called with top cpuset. With cpuset partition that takes CPUs away from the top cpuset, adjusting the cpus_mask of the tasks in the top cpuset is necessary. Percpu kthreads, however, are ignored. Fixes: ee8dde0cd2ce ("cpuset: Add new v2 cpuset.sched.partition flag") Signed-off-by: Waiman Long Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin --- kernel/cgroup/cpuset.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 3213d3c8ea0a..428820bf141d 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -1087,10 +1088,18 @@ static void update_tasks_cpumask(struct cpuset *cs) { struct css_task_iter it; struct task_struct *task; + bool top_cs =3D cs =3D=3D &top_cpuset; =20 css_task_iter_start(&cs->css, 0, &it); - while ((task =3D css_task_iter_next(&it))) + while ((task =3D css_task_iter_next(&it))) { + /* + * Percpu kthreads in top_cpuset are ignored + */ + if (top_cs && (task->flags & PF_KTHREAD) && + kthread_is_per_cpu(task)) + continue; set_cpus_allowed_ptr(task, cs->effective_cpus); + } css_task_iter_end(&it); } =20 @@ -2052,12 +2061,7 @@ static int update_prstate(struct cpuset *cs, int new= _prs) update_flag(CS_CPU_EXCLUSIVE, cs, 0); } =20 - /* - * Update cpumask of parent's tasks except when it is the top - * cpuset as some system daemons cannot be mapped to other CPUs. - */ - if (parent !=3D &top_cpuset) - update_tasks_cpumask(parent); + update_tasks_cpumask(parent); =20 if (parent->child_ecpus_count) update_sibling_cpumasks(parent, cs, &tmpmask); --=20 2.35.1