From nobody Wed Feb 11 08:11:34 2026 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 51531C761A6 for ; Tue, 4 Apr 2023 17:07:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233215AbjDDRHH (ORCPT ); Tue, 4 Apr 2023 13:07:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52764 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233879AbjDDRHD (ORCPT ); Tue, 4 Apr 2023 13:07:03 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2977E12D for ; Tue, 4 Apr 2023 10:06:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1680627981; 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=k8j2HkuWn0j0Z7PhnLLGKz76k+59+HcmFbNhPcenFyw=; b=f1dxsfC3FWlFy3tKVjyILA69Aw+t08YMLykOxKfVMdrowLCNXwIgKT3wuUlm3JPmdpkZa7 BK9hZL9ZfjYZ5VbEq9VyM8cfqWE7FK2QKYku714JyhdNtWS5vzKA+iDyaZA7jDy5sKIwbb rSGKCTjyPb/nq7mc7M//jFzrFgL9+oI= 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-654-Xrcny9mLNxWYG8y8aIzIeQ-1; Tue, 04 Apr 2023 13:06:17 -0400 X-MC-Unique: Xrcny9mLNxWYG8y8aIzIeQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 16BAF185A790; Tue, 4 Apr 2023 17:06:17 +0000 (UTC) Received: from llong.com (unknown [10.22.32.153]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9ABDFFD6E; Tue, 4 Apr 2023 17:06:16 +0000 (UTC) From: Waiman Long To: Tejun Heo , Zefan Li , Johannes Weiner , Christian Brauner Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Juri Lelli , Dietmar Eggemann , =?UTF-8?q?Michal=20Koutn=C3=BD?= , gscrivan@redhat.com, Waiman Long Subject: [PATCH v2 1/4] cgroup/cpuset: Wake up cpuset_attach_wq tasks in cpuset_cancel_attach() Date: Tue, 4 Apr 2023 13:05:43 -0400 Message-Id: <20230404170546.2585050-2-longman@redhat.com> In-Reply-To: <20230404170546.2585050-1-longman@redhat.com> References: <20230404170546.2585050-1-longman@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" After a successful cpuset_can_attach() call which increments the attach_in_progress flag, either cpuset_cancel_attach() or cpuset_attach() will be called later. In cpuset_attach(), tasks in cpuset_attach_wq, if present, will be woken up at the end. That is not the case in cpuset_cancel_attach(). So missed wakeup is possible if the attach operation is somehow cancelled. Fix that by doing the wakeup in cpuset_cancel_attach() as well. Fixes: e44193d39e8d ("cpuset: let hotplug propagation work wait for task at= taching") Signed-off-by: Waiman Long Reviewed-by: Michal Koutn=C3=BD --- kernel/cgroup/cpuset.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index bc4dcfd7bee5..066689a7dcc3 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2507,11 +2507,15 @@ static int cpuset_can_attach(struct cgroup_taskset = *tset) static void cpuset_cancel_attach(struct cgroup_taskset *tset) { struct cgroup_subsys_state *css; + struct cpuset *cs; =20 cgroup_taskset_first(tset, &css); + cs =3D css_cs(css); =20 percpu_down_write(&cpuset_rwsem); - css_cs(css)->attach_in_progress--; + cs->attach_in_progress--; + if (!cs->attach_in_progress) + wake_up(&cpuset_attach_wq); percpu_up_write(&cpuset_rwsem); } =20 --=20 2.31.1