From nobody Wed Dec 24 03:30:32 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AE7E57D411 for ; Thu, 8 Feb 2024 16:10:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707408633; cv=none; b=IqA6a9hOMmoDzpk2KQycR0TYXORIneZGlrz42s0KVrdVjrPqcbTqPGX+Ygdtwp/nA2SYpX8QIt/UuKyCnSSaM9JpwYS1Z3v9Htt7E/OS41Vsujo/TlZ1iw4+TcfAhIE+LztXCp189P2oHQg60HIRovFkvwNB4ekBx7HZFD2vnE4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707408633; c=relaxed/simple; bh=3oS9kSqj13klcEDeru35Hnr/W1vfC6t+2kJTHNu3Y/w=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=fXlKCI4HSqbA4lLbe0dGeRcc8Mo4904PrTcdNHSebjy50aHBxd08gE14XEQwQuICswEHTjifqj5eBm3jcYJNl3iH3knz7eg/hEc1GfuUsqDZQEi99hEquySRYW7oLkuClxDiK4k0JBbsBb7mmtNd5bqxyzLLsyoSOeUNVp9gUTQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=TrQWBEtM; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="TrQWBEtM" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707408630; 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=UVT04WTuQZOL2MdMj2b0Oo6Y1zY5WCBFIOr5ePYEIio=; b=TrQWBEtMFeBNjuuQnY4gzlnOKCXZcmvoHkBsDTwKnEY85bP8h2Pi7vDjDzvGIJvtIbXWzF P838tbL1oim3QJkfO0BnzGM/negEdk5BbbiJ9tDoPM2pWeIFiHZXEzatfMrjmPXzXjimqU pIeZCduXjLhkB/Y2pgL7cIy+NYyIRY8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-516-46iU4v4GPkOENz-AOr_wng-1; Thu, 08 Feb 2024 11:10:27 -0500 X-MC-Unique: 46iU4v4GPkOENz-AOr_wng-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 09CA485A5A8; Thu, 8 Feb 2024 16:10:27 +0000 (UTC) Received: from llong.com (unknown [10.22.32.9]) by smtp.corp.redhat.com (Postfix) with ESMTP id 88FD2492BC6; Thu, 8 Feb 2024 16:10:26 +0000 (UTC) From: Waiman Long To: Tejun Heo , Lai Jiangshan Cc: linux-kernel@vger.kernel.org, Juri Lelli , Cestmir Kalina , Alex Gladkov , Phil Auld , Costa Shulyupin , Waiman Long Subject: [PATCH wq/for-6.9 v5 3/4] kernel/workqueue: Let rescuers follow unbound wq cpumask changes Date: Thu, 8 Feb 2024 11:10:13 -0500 Message-Id: <20240208161014.1084943-4-longman@redhat.com> In-Reply-To: <20240208161014.1084943-1-longman@redhat.com> References: <20240208161014.1084943-1-longman@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.9 Content-Type: text/plain; charset="utf-8" From: Juri Lelli When workqueue cpumask changes are committed the associated rescuer (if one exists) affinity is not touched and this might be a problem down the line for isolated setups. Make sure rescuers affinity is updated every time a workqueue cpumask changes, so that rescuers can't break isolation. [longman: set_cpus_allowed_ptr() will block until the designated task is enqueued on an allowed CPU, no wake_up_process() needed. Also use the unbound_effective_cpumask() helper as suggested by Tejun.] Signed-off-by: Juri Lelli Signed-off-by: Waiman Long --- kernel/workqueue.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index e261acf258b8..8df27c496b63 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -5054,6 +5054,11 @@ static void apply_wqattrs_commit(struct apply_wqattr= s_ctx *ctx) /* update node_nr_active->max */ wq_update_node_max_active(ctx->wq, -1); =20 + /* rescuer needs to respect wq cpumask changes */ + if (ctx->wq->rescuer) + set_cpus_allowed_ptr(ctx->wq->rescuer->task, + unbound_effective_cpumask(ctx->wq)); + mutex_unlock(&ctx->wq->mutex); } =20 --=20 2.39.3