From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CAB90C433EB for ; Thu, 25 Mar 2021 06:59:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B4AB461A21 for ; Thu, 25 Mar 2021 06:59:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230059AbhCYG7R (ORCPT ); Thu, 25 Mar 2021 02:59:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37762 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230032AbhCYG60 (ORCPT ); Thu, 25 Mar 2021 02:58:26 -0400 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 98726C06174A; Wed, 24 Mar 2021 23:58:26 -0700 (PDT) Received: by mail-pj1-x1034.google.com with SMTP id q6-20020a17090a4306b02900c42a012202so515369pjg.5; Wed, 24 Mar 2021 23:58:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :in-reply-to:references; bh=o1CvHWMNIVE9JRrHuZNAemnGtuIBJ5AIryKfD1r6v+8=; b=WhK2TyCXaTs5nWrXgXWnQsFcAVspW+OYbTmTY1PFOrUpXe7RBtPozCnn0xEc5Qy4eE 8yfrTdCLndDjDf18f4IOpLauyPoXRE/W0828gduqXyl2vBp06UZ77uoCknocQdBk5inR dfNe8bQuUdeiTFpTuvsJfP2XKBgDX0Egzn4Rq0agjFHydy27vVfUhGMbaOginJwoFTPo Ke4/UfL/shnb3yXKJjIRHHnJNqWiPIK0Ji1Qx+yKkYUngmycm82Xrm4ew4b9SoWVJwF6 70BDWtIclqhyQxdyAlby3e7B347wzJf2UMdFXxokiZ/6XhkiWAwcn1uf8mV5sNsb90Zg vE5Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=o1CvHWMNIVE9JRrHuZNAemnGtuIBJ5AIryKfD1r6v+8=; b=Gz7JODLh4KkynRE4DC1F05F563FEBvTDz+5XuAp4Vkmeiqny5BhOLjQM+C58pEq9ZJ ldrcR2N2eo9RweCLhVSbclj2/kNOflnAyGaqUwEYKX2Zl7drxIIyetc8My0uQn++ngLF otux8zkA5gXBVgWFenLe/nifohqukYK1Nwr7VyKSiOLpJsc6lYSAyPVm95L6qe/Qu8UX FSjAqmMyOTsKOVTbZfXsSqif9M5E5KQqx8ZvDdjYT5GJL931qVBEmud4cvCqvFkVitHv FbTB4IsUR+BybHXoNr/fok5kli3u64EWzoSdJzjsugI9RQUSqovlSOyNbyFUksEci3qA +XUg== X-Gm-Message-State: AOAM533WOaGp2j7UCR2/Smd2wGOu5qUxKqU9V+X34Z2/UWe5C2ltAwAQ 8mG5OI5NCoGTDnyUU0mIofw/SMDErWojFw== X-Google-Smtp-Source: ABdhPJzUNdaogeNBEnC+EmL59MLkV0as67JwWbBW+WHXYEyRO5zUNhjpHveDJhruO3f/WQEwKYrdUw== X-Received: by 2002:a17:90a:eac7:: with SMTP id ev7mr7501137pjb.158.1616655506236; Wed, 24 Mar 2021 23:58:26 -0700 (PDT) Received: from VM-0-3-centos.localdomain ([101.32.213.191]) by smtp.gmail.com with ESMTPSA id x19sm4470202pfc.152.2021.03.24.23.58.24 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 24 Mar 2021 23:58:25 -0700 (PDT) From: brookxu To: paolo.valente@linaro.org, axboe@kernel.dk, tj@kernel.org Cc: linux-block@vger.kernel.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 14/14] bfq: optimize the calculation of bfq_weight_to_ioprio() Date: Thu, 25 Mar 2021 14:57:58 +0800 Message-Id: <0d36b7d249e0890298e222424f524d3f9bfedbc8.1616649216.git.brookxu@tencent.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: References: In-Reply-To: References: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chunguang Xu The value range of ioprio is [0, 7], but the result of bfq_weight_to_ioprio() may exceed this range, so simple optimization is required. Signed-off-by: Chunguang Xu --- block/bfq-wf2q.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c index b477a9b..1b91c8b 100644 --- a/block/bfq-wf2q.c +++ b/block/bfq-wf2q.c @@ -586,8 +586,9 @@ unsigned short bfq_ioprio_to_weight(int ioprio) */ static unsigned short bfq_weight_to_ioprio(int weight) { - return max_t(int, 0, - IOPRIO_BE_NR * BFQ_WEIGHT_CONVERSION_COEFF - weight); + int ioprio = IOPRIO_BE_NR - weight / BFQ_WEIGHT_CONVERSION_COEFF; + + return ioprio < 0 ? 0 : min_t(int, ioprio, IOPRIO_BE_NR - 1); } static void bfq_get_entity(struct bfq_entity *entity) -- 1.8.3.1