From patchwork Tue Jun 27 14:35:00 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Waiman Long X-Patchwork-Id: 13294617 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 DDBCEEB64D9 for ; Tue, 27 Jun 2023 14:43:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231918AbjF0Ond (ORCPT ); Tue, 27 Jun 2023 10:43:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231848AbjF0OnS (ORCPT ); Tue, 27 Jun 2023 10:43:18 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A1723AAC for ; Tue, 27 Jun 2023 07:42:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1687876855; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HxXXRG19n9JIA9MH1iFO6LWghYV5obKh5ig/aXiH0Xo=; b=M0sIQLfwrWbtHzV0qUWLeOGwSx+mbBeICu5GFz2/4/npZwq528Lkll2hcUoMHEb44WYutK 5z7yg6neUsAUyr9gzP6xUvLNvG34vHf2UY3nhtsLuu+NCKFBO2tT00DzsDUFXRhrxfgZZq siBDrAZOE/FMDZ+YOrPRTUp5yFYjjQw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-433-LmQfQh6XPPu43T56nk_XGA-1; Tue, 27 Jun 2023 10:40:51 -0400 X-MC-Unique: LmQfQh6XPPu43T56nk_XGA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B1A458C810A; Tue, 27 Jun 2023 14:35:32 +0000 (UTC) Received: from llong.com (unknown [10.22.10.32]) by smtp.corp.redhat.com (Postfix) with ESMTP id DDBCE40C2063; Tue, 27 Jun 2023 14:35:31 +0000 (UTC) From: Waiman Long To: Tejun Heo , Zefan Li , Johannes Weiner , Jonathan Corbet , Shuah Khan Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Juri Lelli , Valentin Schneider , Frederic Weisbecker , Mrunal Patel , Ryan Phillips , Brent Rowsell , Peter Hunt , Phil Auld , Waiman Long Subject: [PATCH v4 1/9] cgroup/cpuset: Inherit parent's load balance state in v2 Date: Tue, 27 Jun 2023 10:35:00 -0400 Message-Id: <20230627143508.1576882-2-longman@redhat.com> In-Reply-To: <20230627143508.1576882-1-longman@redhat.com> References: <20230627143508.1576882-1-longman@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Since commit f28e22441f35 ("cgroup/cpuset: Add a new isolated cpus.partition type"), the CS_SCHED_LOAD_BALANCE bit of a v2 cpuset can be on or off. The child cpusets of a partition root must have the same setting as its parent or it may screw up the rebuilding of sched domains. Fix this problem by making sure the a child v2 cpuset will follows its parent cpuset load balance state unless the child cpuset is a new partition root itself. Fixes: f28e22441f35 ("cgroup/cpuset: Add a new isolated cpus.partition type") Signed-off-by: Waiman Long --- kernel/cgroup/cpuset.c | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 58e6f18f01c1..170e342b07e3 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1588,11 +1588,16 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp, } /* - * Skip the whole subtree if the cpumask remains the same - * and has no partition root state and force flag not set. + * Skip the whole subtree if + * 1) the cpumask remains the same, + * 2) has no partition root state, + * 3) force flag not set, and + * 4) for v2 load balance state same as its parent. */ if (!cp->partition_root_state && !force && - cpumask_equal(tmp->new_cpus, cp->effective_cpus)) { + cpumask_equal(tmp->new_cpus, cp->effective_cpus) && + (!cgroup_subsys_on_dfl(cpuset_cgrp_subsys) || + (is_sched_load_balance(parent) == is_sched_load_balance(cp)))) { pos_css = css_rightmost_descendant(pos_css); continue; } @@ -1675,6 +1680,20 @@ static void update_cpumasks_hier(struct cpuset *cs, struct tmpmasks *tmp, update_tasks_cpumask(cp, tmp->new_cpus); + /* + * On default hierarchy, inherit the CS_SCHED_LOAD_BALANCE + * from parent if current cpuset isn't a valid partition root + * and their load balance states differ. + */ + if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys) && + !is_partition_valid(cp) && + (is_sched_load_balance(parent) != is_sched_load_balance(cp))) { + if (is_sched_load_balance(parent)) + set_bit(CS_SCHED_LOAD_BALANCE, &cp->flags); + else + clear_bit(CS_SCHED_LOAD_BALANCE, &cp->flags); + } + /* * On legacy hierarchy, if the effective cpumask of any non- * empty cpuset is changed, we need to rebuild sched domains. @@ -3222,6 +3241,14 @@ static int cpuset_css_online(struct cgroup_subsys_state *css) cs->use_parent_ecpus = true; parent->child_ecpus_count++; } + + /* + * For v2, clear CS_SCHED_LOAD_BALANCE if parent is isolated + */ + if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys) && + !is_sched_load_balance(parent)) + clear_bit(CS_SCHED_LOAD_BALANCE, &cs->flags); + spin_unlock_irq(&callback_lock); if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags))