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=-15.7 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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 B5631C4321A for ; Fri, 12 Mar 2021 11:09:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A1BF65038 for ; Fri, 12 Mar 2021 11:09:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234109AbhCLLJY (ORCPT ); Fri, 12 Mar 2021 06:09:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233736AbhCLLJP (ORCPT ); Fri, 12 Mar 2021 06:09:15 -0500 Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65B44C061574; Fri, 12 Mar 2021 03:09:15 -0800 (PST) Received: by mail-pg1-x52c.google.com with SMTP id o38so15626994pgm.9; Fri, 12 Mar 2021 03:09:15 -0800 (PST) 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=ZEYL/pbFIoRQQHylJZyb6mvpBG/vJ0CzVs8U+fDkQms=; b=fDVgcd6CradPpZOVQhUMVl1zY6XDbhFqMkk4LY+ex6E56v/JqmtuN+XcpqYkN0QxU8 eOv3acgR/VQTPgS+YCZlSYLiwXSLKMSCBcguGL40LJ6EOBXrvWHegtWndkARFq8ZVQ1Q rcJ99csDt8f0DX2tAYsw0iJ4T2CAGL66fx6rvQx6PEz0Nkzo/KfWE0Gam//0TeEtYzZQ xvyYfViiR6iAuln08vPKuT+id9NBl+Zwu2JJxZEkOEZ8/RXIKj9UtpWHvAv0zuLkfupT Elq1xJxBCFfVQidEQUGLC1gcHQbQXy/EIcmK0WTWhplSm0Ak+/hgpJf3MjptOgn7T/fg O07Q== 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=ZEYL/pbFIoRQQHylJZyb6mvpBG/vJ0CzVs8U+fDkQms=; b=r8dwvgH859MKwKA+yF3D25/3QMLoE5SujAqE8T3I05iJgZ0bwh800j9aTfzp+aAQVP r5vrCuUu0GrcEakO/7YxMKqeGAKbLXxIXpiP9b37FoazsJVqu1B/Rpi1GolX7GlOxgHm Tb1+B2I0b5IBMy6uleq2N+hGr1w+JdePQ//wIVn612XjbcVEiutmQ6luL3KjqRQQxJJc DvFd5Um7grbDZFctHjczssSeZx1DQDk6MOGTvic2ttA7oyeTHK6HCbpG/YVpKgs72bH8 rW8IPpkK4hyv7rgzasucGVonkO/Ie9ixtpMa20spxQ5V5EBHpfA3qT0WQJMRXjtJrTom 7thg== X-Gm-Message-State: AOAM532g7GNAtEv7UYh+uyrc2VOzVLZ0BuI5vBDuR4Yg6B3I2js63pem 2hwG3Y1apcdzcl/AROr0roP9TEiz5pMwfw== X-Google-Smtp-Source: ABdhPJw+YrsbC3H4O1aCuj7GJv0goHt0TbNgi6zhIsUyNlKRzie8i1hXPGLPWMgqibDXPP5xGFEvbw== X-Received: by 2002:a63:b1c:: with SMTP id 28mr11292784pgl.165.1615547354950; Fri, 12 Mar 2021 03:09:14 -0800 (PST) Received: from VM-0-3-centos.localdomain ([101.32.213.191]) by smtp.gmail.com with ESMTPSA id t5sm4942181pgl.89.2021.03.12.03.09.11 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 12 Mar 2021 03:09:13 -0800 (PST) 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: [RFC PATCH v2 11/11] bfq: optimize the calculation of bfq_weight_to_ioprio() Date: Fri, 12 Mar 2021 19:08:45 +0800 Message-Id: <29efad299fd111b38ad215dcbc6eb506290e7937.1615527324.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-block@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 f6c67a80e454..86558a8fede1 100644 --- a/block/bfq-wf2q.c +++ b/block/bfq-wf2q.c @@ -536,8 +536,9 @@ 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) -- 2.30.0