From nobody Sun Feb 8 14:10:12 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 3B6FC1B95B for ; Wed, 7 Feb 2024 01:19:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707268781; cv=none; b=Zl8jq+/FQlow4HZs9HnzJUB+AyU+KD56VTNRMAaORcLAgTGpjcTj0YShtCy1J5GG10anVy9WpVD/AW9czQ15z9BrLocjee5h/8VaviUpyBbUQj7UnlPOQl5k4QixBloxvaMYdqPSdWJNpnbXhqjgNCC7BP+EFY9ca/LLA7Lr1RY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707268781; c=relaxed/simple; bh=FS+l524qoBFbVz1FfbcQ2i0NBRG/MdSdZhRbd/PgfWA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=lUtMiVrZ42epUvre2g9XleIRHVB4GaxHEUsBbBx05I63fH1FcITtFrVPRHV2CsdscNo2Bcpr8C/RlWgxBH3HRSL0TkVzVB2OSZ6fcusahHtFU070s7gqiW7svmZOQCRXlWWabANbL3gFP87pPc0oGbPudfoWRKuAPkwmMMdSmT0= 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=a93f2x24; arc=none smtp.client-ip=170.10.129.124 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="a93f2x24" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1707268779; 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=vJQWPdqy08UQ8K2twJy9pwfGNKDdokiadGdxmJITQUM=; b=a93f2x24Sw81Gh/wSK/QjTOtDKgf1UrWDsRaaZZD7tz+ncEKYuvejZEyuR33mHlZyPte2C TiqXb9yOFYPaU1HYCt2ahTeeS/gZiN6qWJyi96cxblXCfWK//P/9/VaOSPnJE3y6JACigH XipJez7eKOk3U/Gz15ceoyHAFAKjdso= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-455-3g99GikHP0uEyRJ_BmBzXA-1; Tue, 06 Feb 2024 20:19:34 -0500 X-MC-Unique: 3g99GikHP0uEyRJ_BmBzXA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (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 CA4311C04B4C; Wed, 7 Feb 2024 01:19:33 +0000 (UTC) Received: from llong.com (unknown [10.22.16.53]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4E18640D1B60; Wed, 7 Feb 2024 01:19:33 +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 v4 3/4] kernel/workqueue: Let rescuers follow unbound wq cpumask changes Date: Tue, 6 Feb 2024 20:19:10 -0500 Message-Id: <20240207011911.975608-4-longman@redhat.com> In-Reply-To: <20240207011911.975608-1-longman@redhat.com> References: <20240207011911.975608-1-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 10.11.54.2 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 49fe082fe328..3044ad6f9496 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -5084,6 +5084,11 @@ 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