From patchwork Fri Apr 8 07:39:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12806205 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 A13A9C433EF for ; Fri, 8 Apr 2022 07:24:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229913AbiDHH05 (ORCPT ); Fri, 8 Apr 2022 03:26:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229870AbiDHH0s (ORCPT ); Fri, 8 Apr 2022 03:26:48 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C24C036A468; Fri, 8 Apr 2022 00:24:44 -0700 (PDT) Received: from kwepemi100002.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4KZV8K4MVNzgYYr; Fri, 8 Apr 2022 15:22:57 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by kwepemi100002.china.huawei.com (7.221.188.188) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 8 Apr 2022 15:24:42 +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 15.1.2308.21; Fri, 8 Apr 2022 15:24:42 +0800 From: Yu Kuai To: , , , , CC: , , Subject: [PATCH -next RFC v2 8/8] sbitmap: wake up the number of threads based on required tags Date: Fri, 8 Apr 2022 15:39:16 +0800 Message-ID: <20220408073916.1428590-9-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220408073916.1428590-1-yukuai3@huawei.com> References: <20220408073916.1428590-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) 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 Always wake up 'wake_batch' threads will intensify competition and split io won't be issued continuously. Now that how many tags is required is recorded for huge io, it's safe to wake up baed on required tags. Signed-off-by: Yu Kuai --- lib/sbitmap.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/lib/sbitmap.c b/lib/sbitmap.c index 8d01e02ea4b1..eac9fa5c2b4d 100644 --- a/lib/sbitmap.c +++ b/lib/sbitmap.c @@ -614,6 +614,26 @@ static inline void sbq_update_preemption(struct sbitmap_queue *sbq, WRITE_ONCE(sbq->force_tag_preemption, force); } +static unsigned int get_wake_nr(struct sbq_wait_state *ws, unsigned int nr_tags) +{ + struct sbq_wait *wait; + struct wait_queue_entry *entry; + unsigned int nr = 1; + + spin_lock_irq(&ws->wait.lock); + list_for_each_entry(entry, &ws->wait.head, entry) { + wait = container_of(entry, struct sbq_wait, wait); + if (nr_tags <= wait->nr_tags) + break; + + nr++; + nr_tags -= wait->nr_tags; + } + spin_unlock_irq(&ws->wait.lock); + + return nr; +} + static bool __sbq_wake_up(struct sbitmap_queue *sbq) { struct sbq_wait_state *ws; @@ -648,7 +668,7 @@ static bool __sbq_wake_up(struct sbitmap_queue *sbq) smp_mb__before_atomic(); atomic_set(&ws->wait_cnt, wake_batch); sbq_update_preemption(sbq, wake_batch); - wake_up_nr(&ws->wait, wake_batch); + wake_up_nr(&ws->wait, get_wake_nr(ws, wake_batch)); return true; }