From patchwork Sun Feb 19 10:42:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kemeng Shi X-Patchwork-Id: 13145762 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 B3479C64ED6 for ; Sun, 19 Feb 2023 02:41:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229628AbjBSCl3 (ORCPT ); Sat, 18 Feb 2023 21:41:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229441AbjBSCl2 (ORCPT ); Sat, 18 Feb 2023 21:41:28 -0500 Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27F4411EA1; Sat, 18 Feb 2023 18:41:26 -0800 (PST) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4PK8v456gdz4f3lbQ; Sun, 19 Feb 2023 10:41:20 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP2 (Coremail) with SMTP id Syh0CgBH7utQjPFjPmleDw--.7604S4; Sun, 19 Feb 2023 10:41:22 +0800 (CST) From: Kemeng Shi To: paolo.valente@linaro.org, axboe@kernel.dk, jack@suse.cz Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, shikemeng@huaweicloud.com Subject: [PATCH 02/17] block, bfq: try preemption if bfqq has higher weight and the same priority class Date: Sun, 19 Feb 2023 18:42:54 +0800 Message-Id: <20230219104309.1511562-3-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20230219104309.1511562-1-shikemeng@huaweicloud.com> References: <20230219104309.1511562-1-shikemeng@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: Syh0CgBH7utQjPFjPmleDw--.7604S4 X-Coremail-Antispam: 1UD129KBjvJXoW7AF4xWF43Cw4fZFW7Wr13CFg_yoW8GrykpF 9rG3yUWr17CF4ru3WUJFnavrWrWas3GrnrJrs3ua18CrWUZrnruF9Ik3s3ZF4Igr1IqF4a qr10qr9rX3W5Xw7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPSb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M280x2IEY4vEnII2IxkI6r1a6r45M2 8IrcIa0xkI8VA2jI8067AKxVWUXwA2048vs2IY020Ec7CjxVAFwI0_Gr0_Xr1l8cAvFVAK 0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4 x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l 84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I 8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AK xVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zV CS5cI20VAGYxC7MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E 5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUAV WUtwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY 1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI 0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7s RNVbyUUUUUU== X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org We will compare priority class and weight of current bfqq with in_service_queue to check if bfqq could preempt in_service_queue. Currently we will try to preempt in_service_queue if bfqq has higher weight than in_service_queue even with lower priority class. Actually, we will only serve bfqq with higher priority class (see bfq_lookup_next_entity), so bfqq with higher weight and lower priority class will not be a candidate to preempt in_service_queue. Compare weight of bfqqs with the same priority in bfq_bfqq_higher_class_or_weight to make preemption check more reasonable. Signed-off-by: Kemeng Shi --- block/bfq-iosched.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 3f5c740664ce..4868538c9745 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -1768,6 +1768,10 @@ static bool bfq_bfqq_higher_class_or_weight(struct bfq_queue *bfqq, if (bfqq->ioprio_class < in_serv_bfqq->ioprio_class) return true; + /* only try weight comparison with same priority class */ + if (bfqq->ioprio_class != in_serv_bfqq->ioprio_class) + return false; + if (in_serv_bfqq->entity.parent == bfqq->entity.parent) { bfqq_weight = bfqq->entity.weight; in_serv_weight = in_serv_bfqq->entity.weight;