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=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 E7C42C4160E for ; Mon, 8 Mar 2021 12:01:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C543B651CF for ; Mon, 8 Mar 2021 12:01:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231983AbhCHMAw (ORCPT ); Mon, 8 Mar 2021 07:00:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231506AbhCHMAh (ORCPT ); Mon, 8 Mar 2021 07:00:37 -0500 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E09FC06174A; Mon, 8 Mar 2021 04:00:37 -0800 (PST) Received: by mail-pj1-x1030.google.com with SMTP id x7-20020a17090a2b07b02900c0ea793940so2845314pjc.2; Mon, 08 Mar 2021 04:00:37 -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=MsMrEc4lTH47pfPngVwGfQNjeTIkU6svvwLN8Qg8P28=; b=mUhvT0FPrBG4HiXW7y9J5WZyUFm+kOkubtMISyASrxvxjTNSoam06f4EeFpOTS9Wuu thpfbVouSfVT7cXTmuRE0ohBa+/AQ9VhaFZOlbfshF66qKj3i/jrFp+7PmvcXJTYmWMH Oq0ZYBzYVY1mLPzsORhJjSK+oXkkGmW1g9lLklufsnikuAli+fxEkJopncvjQS5IQswZ nviudM05sIkbc5fpXP1pyW6CIgEfa8C2NDWAtX9Wh9JBwl+9SpRfaWAPVhT1gIfrWqqn EPlA51MNz2CDinh4BlhkmljgFeXQQan01LmYCGkmcL8xscJQxoRNLfPAzXVfKUv7KcaA 3Rvw== 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=MsMrEc4lTH47pfPngVwGfQNjeTIkU6svvwLN8Qg8P28=; b=D776WW47KlHN/Oyxp5WtgIHBAupImub25sxm8la8cJCpiqC0vYlOB0o1oKP39yF3rb 0TBHSmNu9huOQqvTPfgRrIC2vM39BWq8KjtMNNslsjmOZO+lP8ADCpDOh3YTlunMoaL1 3V6ix5gjbJxPcawCYr6lA6Zrmr/55RGZoCvLJmRtZDbL3ONKvub213lCPaUp2yU/rhzS GWeQjbcV3g9KZy+QIBiU3S7eDdRK1BuJY7/IcemmA8XzHmSvYBQ8juGSGd2wK83lm99F Q1vwXrIy6SUc8phl9BkOac/NCUPR93Ust8jLDi0UyLIFnnkOfWMJUTBGPwo4x+crr6Vk /E+Q== X-Gm-Message-State: AOAM530v4Zq1aqv2mMdRV3b3vbQhDo2+/cuAXddBBoYKqRFcrB4HUtJK 2wgeyvu1gzGoZL6hTPBwIKU= X-Google-Smtp-Source: ABdhPJxvsaf5aIPY3hQ7qCbFu6yAlYxbnCazDOJ0goZnSwJtQXW1GFOHDr8iU/9EgYJ4dp7vAiZMvA== X-Received: by 2002:a17:90a:598e:: with SMTP id l14mr23872714pji.187.1615204836865; Mon, 08 Mar 2021 04:00:36 -0800 (PST) Received: from VM-0-3-centos.localdomain ([101.32.213.191]) by smtp.gmail.com with ESMTPSA id mp19sm22570855pjb.2.2021.03.08.04.00.35 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 08 Mar 2021 04:00:36 -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 8/8] bfq: optimize the calculation of bfq_weight_to_ioprio() Date: Mon, 8 Mar 2021 20:00:21 +0800 Message-Id: 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 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 850a8e2f0bda..1d565daf516f 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