From patchwork Fri Dec 16 11:12:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kemeng Shi X-Patchwork-Id: 13074737 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 C24DBC4167B for ; Fri, 16 Dec 2022 03:13:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229849AbiLPDNg (ORCPT ); Thu, 15 Dec 2022 22:13:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229752AbiLPDNe (ORCPT ); Thu, 15 Dec 2022 22:13:34 -0500 Received: from dggsgout12.his.huawei.com (unknown [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 793482A951; Thu, 15 Dec 2022 19:13:32 -0800 (PST) Received: from mail02.huawei.com (unknown [172.30.67.153]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4NYDh56xhDz4f43lq; Fri, 16 Dec 2022 11:13:25 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgAXiNVW4ptjHYxACQ--.50238S3; Fri, 16 Dec 2022 11:13:29 +0800 (CST) From: Kemeng Shi To: jack@suse.cz, paolo.valente@linaro.org, tj@kernel.org, josef@toxicpanda.com, axboe@kernel.dk Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linfeilong@huawei.com, liuzhiqiang@26.com, shikemeng@huaweicloud.com Subject: [PATCH v2 01/10] block, bfq: correctly raise inject limit in bfq_choose_bfqq_for_injection Date: Fri, 16 Dec 2022 19:12:21 +0800 Message-Id: <20221216111230.3638832-2-shikemeng@huaweicloud.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20221216111230.3638832-1-shikemeng@huaweicloud.com> References: <20221216111230.3638832-1-shikemeng@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: gCh0CgAXiNVW4ptjHYxACQ--.50238S3 X-Coremail-Antispam: 1UD129KBjvJXoW7uF4xCr1xXrWruF18AF45trb_yoW8Zr1rpa y7K347C34xJF1ruF1jqa1fZFyYqan3Crnrtr13W34Fvryxur92gas2g3y5Za1fKFs3Aw4j va4UWa4q9F1YkaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUmmb4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M280x2IEY4vEnII2IxkI6r1a6r45M2 8IrcIa0xkI8VA2jI8067AKxVWUGwA2048vs2IY020Ec7CjxVAFwI0_Gr0_Xr1l8cAvFVAK 0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4 x0Y4vE2Ix0cI8IcVCY1x0267AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28E F7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F4 0EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_ Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc 8vx2IErcIFxwACI402YVCY1x02628vn2kIc2xKxwCF04k20xvY0x0EwIxGrwCFx2IqxVCF s4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r 1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWU JVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r 1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1U YxBIdaVFxhVjvjDU0xZFpf9x0pimhFUUUUUU= X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Function bfq_choose_bfqq_for_injection may temporarily raise inject limit to one request if current inject_limit is 0 before search of the source queue for injection. However the search below will reset inject limit to bfqd->in_service_queue which is zero for raised inject limit. Then the temporarily raised inject limit never works as expected. Assigment limit to bfqd->in_service_queue in search is needed as limit maybe overwriten to min_t(unsigned int, 1, limit) for condition that a large in-flight request is on non-rotational devices in found queue. So we need to reset limit to bfqd->in_service_queue for normal case. Actually, we have already make sure bfqd->rq_in_driver is < limit before search, then -Limit is >= 1 as bfqd->rq_in_driver is >= 0. Then min_t(unsigned int, 1, limit) is always 1. So we can simply check bfqd->rq_in_driver with 1 instead of result of min_t(unsigned int, 1, limit) for larget request in non-rotational device case to avoid overwritting limit and the bug is gone. -For normal case, we have already check bfqd->rq_in_driver is < limit, so we can return found bfqq unconditionally to remove unncessary check. Signed-off-by: Kemeng Shi --- block/bfq-iosched.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index a72304c728fc..1220c41fc767 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -4641,12 +4641,10 @@ bfq_choose_bfqq_for_injection(struct bfq_data *bfqd) */ if (blk_queue_nonrot(bfqd->queue) && blk_rq_sectors(bfqq->next_rq) >= - BFQQ_SECT_THR_NONROT) - limit = min_t(unsigned int, 1, limit); - else - limit = in_serv_bfqq->inject_limit; - - if (bfqd->rq_in_driver < limit) { + BFQQ_SECT_THR_NONROT && + bfqd->rq_in_driver >= 1) + continue; + else { bfqd->rqs_injected = true; return bfqq; }