From patchwork Tue Nov 1 09:34:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kemeng Shi X-Patchwork-Id: 13026778 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 AC51BFA373D for ; Tue, 1 Nov 2022 09:35:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229645AbiKAJfC (ORCPT ); Tue, 1 Nov 2022 05:35:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230063AbiKAJen (ORCPT ); Tue, 1 Nov 2022 05:34:43 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EB09119027; Tue, 1 Nov 2022 02:34:30 -0700 (PDT) Received: from kwepemi500016.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4N1l8r705dzRnsb; Tue, 1 Nov 2022 17:29:32 +0800 (CST) Received: from huawei.com (10.174.178.129) 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 15.1.2375.31; Tue, 1 Nov 2022 17:34:28 +0800 From: Kemeng Shi To: , CC: , , Subject: [PATCH 15/20] block, bfq: some cleanups for function bfq_pos_tree_add_move Date: Tue, 1 Nov 2022 17:34:12 +0800 Message-ID: <20221101093417.10540-16-shikemeng@huawei.com> X-Mailer: git-send-email 2.14.1.windows.1 In-Reply-To: <20221101093417.10540-1-shikemeng@huawei.com> References: <20221101093417.10540-1-shikemeng@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.174.178.129] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemi500016.china.huawei.com (7.221.188.220) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org There are three cleanups in this patch: 1. The oom_bfqq is never inserted to tree, so return immediately for oom_bfqq before unnecessary NULL check of bfqq->pos_root. 2. Only set bfqq->pos_root after bfq_rq_pos_tree_lookup successes rather than set bfqq->pos_root unconditionally and reset to NULL if bfq_rq_pos_tree_lookup fails. 3. Remove unnecessary local variable __bfqq which is only used to check return value of bfq_rq_pos_tree_lookup. Signed-off-by: Kemeng Shi --- block/bfq-iosched.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 776951156fbc..dd9a51255a0f 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -758,17 +758,16 @@ void __cold bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq) { struct rb_node **p, *parent; - struct bfq_queue *__bfqq; + + /* oom_bfqq does not participate in queue merging */ + if (bfqq == &bfqd->oom_bfqq) + return; if (bfqq->pos_root) { rb_erase(&bfqq->pos_node, bfqq->pos_root); bfqq->pos_root = NULL; } - /* oom_bfqq does not participate in queue merging */ - if (bfqq == &bfqd->oom_bfqq) - return; - /* * bfqq cannot be merged any longer (see comments in * bfq_setup_cooperator): no point in adding bfqq into the @@ -782,14 +781,13 @@ bfq_pos_tree_add_move(struct bfq_data *bfqd, struct bfq_queue *bfqq) if (!bfqq->next_rq) return; + if (bfq_rq_pos_tree_lookup(bfqd, &bfqq_group(bfqq)->rq_pos_tree, + blk_rq_pos(bfqq->next_rq), &parent, &p)) + return; + bfqq->pos_root = &bfqq_group(bfqq)->rq_pos_tree; - __bfqq = bfq_rq_pos_tree_lookup(bfqd, bfqq->pos_root, - blk_rq_pos(bfqq->next_rq), &parent, &p); - if (!__bfqq) { - rb_link_node(&bfqq->pos_node, parent, p); - rb_insert_color(&bfqq->pos_node, bfqq->pos_root); - } else - bfqq->pos_root = NULL; + rb_link_node(&bfqq->pos_node, parent, p); + rb_insert_color(&bfqq->pos_node, bfqq->pos_root); } /*