From patchwork Sat Jan 29 01:59:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12729353 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 B5DEFC433FE for ; Sat, 29 Jan 2022 01:48:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352102AbiA2Bsp (ORCPT ); Fri, 28 Jan 2022 20:48:45 -0500 Received: from szxga03-in.huawei.com ([45.249.212.189]:32131 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352083AbiA2Bsm (ORCPT ); Fri, 28 Jan 2022 20:48:42 -0500 Received: from kwepemi500016.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Jlxx05GsFz8wWB; Sat, 29 Jan 2022 09:45:40 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by kwepemi500016.china.huawei.com (7.221.188.220) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Sat, 29 Jan 2022 09:48:40 +0800 Received: from huawei.com (10.175.127.227) by kwepemm600009.china.huawei.com (7.193.23.164) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.21; Sat, 29 Jan 2022 09:48:39 +0800 From: Yu Kuai To: , , CC: , , , , Subject: [PATCH v3 2/3] block, bfq: avoid moving bfqq to it's parent bfqg Date: Sat, 29 Jan 2022 09:59:23 +0800 Message-ID: <20220129015924.3958918-3-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220129015924.3958918-1-yukuai3@huawei.com> References: <20220129015924.3958918-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemm600009.china.huawei.com (7.193.23.164) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Moving bfqq to it's parent bfqg is pointless. Signed-off-by: Yu Kuai --- block/bfq-cgroup.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c index 24a5c5329bcd..9783c1156159 100644 --- a/block/bfq-cgroup.c +++ b/block/bfq-cgroup.c @@ -645,6 +645,14 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, struct bfq_group *bfqg) { struct bfq_entity *entity = &bfqq->entity; + struct bfq_group *old_parent = bfqq_group(bfqq); + + /* + * No point to move bfqq to the same group, which can happen when + * root group is offlined + */ + if (old_parent == bfqg) + return; /* * Get extra reference to prevent bfqq from being freed in @@ -666,7 +674,7 @@ void bfq_bfqq_move(struct bfq_data *bfqd, struct bfq_queue *bfqq, bfq_deactivate_bfqq(bfqd, bfqq, false, false); else if (entity->on_st_or_in_serv) bfq_put_idle_entity(bfq_entity_service_tree(entity), entity); - bfqg_and_blkg_put(bfqq_group(bfqq)); + bfqg_and_blkg_put(old_parent); if (entity->parent && entity->parent->last_bfqq_created == bfqq)