From patchwork Fri Jun 10 02:17:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12876310 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 13253CCA47B for ; Fri, 10 Jun 2022 02:04:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345887AbiFJCEZ (ORCPT ); Thu, 9 Jun 2022 22:04:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45920 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345916AbiFJCEP (ORCPT ); Thu, 9 Jun 2022 22:04:15 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B083E8A30F; Thu, 9 Jun 2022 19:03:54 -0700 (PDT) Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4LK43x2MVTzjX9C; Fri, 10 Jun 2022 10:02:53 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by dggemv711-chm.china.huawei.com (10.1.198.66) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 10 Jun 2022 10:03:52 +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 15.1.2375.24; Fri, 10 Jun 2022 10:03:51 +0800 From: Yu Kuai To: , , , CC: , , , , Subject: [PATCH -next v10 4/4] block, bfq: do not idle if only one group is activated Date: Fri, 10 Jun 2022 10:17:01 +0800 Message-ID: <20220610021701.2347602-5-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220610021701.2347602-1-yukuai3@huawei.com> References: <20220610021701.2347602-1-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 Now that root group is counted into 'num_groups_with_pending_reqs', 'num_groups_with_pending_reqs > 0' is always true in bfq_asymmetric_scenario(). Thus change the condition to '> 1'. On the other hand, this change can enable concurrent sync io if only one group is activated. Signed-off-by: Yu Kuai Reviewed-by: Jan Kara --- block/bfq-iosched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 03b04892440c..a2aa243505dc 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -820,7 +820,7 @@ bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq) * much easier to maintain the needed state: * 1) all active queues have the same weight, * 2) all active queues belong to the same I/O-priority class, - * 3) there are no active groups. + * 3) there is at most one active group. * In particular, the last condition is always true if hierarchical * support or the cgroups interface are not enabled, thus no state * needs to be maintained in this case. @@ -852,7 +852,7 @@ static bool bfq_asymmetric_scenario(struct bfq_data *bfqd, return varied_queue_weights || multiple_classes_busy #ifdef CONFIG_BFQ_GROUP_IOSCHED - || bfqd->num_groups_with_pending_reqs > 0 + || bfqd->num_groups_with_pending_reqs > 1 #endif ; }