From patchwork Sun Feb 19 10:42:56 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kemeng Shi X-Patchwork-Id: 13145765 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 100E6C64ED9 for ; Sun, 19 Feb 2023 02:41:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229557AbjBSClb (ORCPT ); Sat, 18 Feb 2023 21:41:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42274 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229588AbjBSCl2 (ORCPT ); Sat, 18 Feb 2023 21:41:28 -0500 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 67EC212043; Sat, 18 Feb 2023 18:41:26 -0800 (PST) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4PK8v53SpCz4f3p1G; Sun, 19 Feb 2023 10:41:21 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP2 (Coremail) with SMTP id Syh0CgBH7utQjPFjPmleDw--.7604S6; Sun, 19 Feb 2023 10:41:23 +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 04/17] block, bfq: recover the "service hole" if enough budget is left Date: Sun, 19 Feb 2023 18:42:56 +0800 Message-Id: <20230219104309.1511562-5-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--.7604S6 X-Coremail-Antispam: 1UD129KBjvJXoW7ZF48ury5Kw18CFWfAF4kXrb_yoW8XF18pa 9rKryS9rn5WFn8Xa1Iv3W3X34rX3Wfury7t3yFv3yrJa9xZw129F4ay345tayIqFZ7trWa vr1DXryUWw4UZrJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPY14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2jI8I6cxK62vIxIIY0VWUZVW8XwA2048vs2IY02 0E87I2jVAFwI0_JF0E3s1l82xGYIkIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0 rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6x IIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xv wVC2z280aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFc xC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_ Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2 IErcIFxwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E 14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_Jw1lIx kGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAF wI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r1j6r 4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0pRvJPtU UUUU= X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org If budget left is less than budget need by next request, the activated bfqq will be expired if it preempts the in-service queue. Avoid to cause useless overhead to check budget left is enough for next request. Signed-off-by: Kemeng Shi --- block/bfq-iosched.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 7b416f9471b3..edbf5c9aeb47 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -1588,13 +1588,15 @@ static bool bfq_bfqq_update_budg_for_activation(struct bfq_data *bfqd, /* * In the next compound condition, we check also whether there - * is some budget left, because otherwise there is no point in - * trying to go on serving bfqq with this same budget: bfqq - * would be expired immediately after being selected for - * service. This would only cause useless overhead. + * is some budget left for next request to serve, because + * otherwise there is no point in trying to go on serving bfqq + * with this same budget: bfqq would be expired immediately + * after being selected for service. This would only cause + * useless overhead. */ if (bfq_bfqq_non_blocking_wait_rq(bfqq) && arrived_in_time && - bfq_bfqq_budget_left(bfqq) > 0) { + bfq_bfqq_budget_left(bfqq) >= + bfq_serv_to_charge(bfqq->next_rq, bfqq)) { /* * We do not clear the flag non_blocking_wait_rq here, as * the latter is used in bfq_activate_bfqq to signal