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=-5.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 BAFD1C64E7C for ; Wed, 2 Dec 2020 19:45:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 64E1122240 for ; Wed, 2 Dec 2020 19:45:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389606AbgLBTp1 (ORCPT ); Wed, 2 Dec 2020 14:45:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35496 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728940AbgLBTp1 (ORCPT ); Wed, 2 Dec 2020 14:45:27 -0500 Received: from mail-io1-xd44.google.com (mail-io1-xd44.google.com [IPv6:2607:f8b0:4864:20::d44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F246DC0617A6 for ; Wed, 2 Dec 2020 11:44:40 -0800 (PST) Received: by mail-io1-xd44.google.com with SMTP id t8so3188046iov.8 for ; Wed, 02 Dec 2020 11:44:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=QyEPDAytTEl0uopebdyNHFfe+27dQnLC51NhV3dnBlQ=; b=OBM1e4X4T5ctyaC99rN18qygJBuxT+Na4CBNEK0YrhauMduyrFTBQhoBjaEMQ9gkgP RJDGNWlQZUoeYB18Zc8lohe07PWMzXOXi36725jdFTsya/BtObnqro1yRkyJ+pPO4K4m 2Key7R6FaAFR5VWNEtq5Q8UX8qafo/GEDz6cEwX68EMT3OyNwoakm1ExLrjmVVqzAkX5 TeGUe2RLSQvwYYvowut5+1w4CA2CMErINS9xnd5OutfEFUpKZ1U5Rb+h7ImZFTFCrloo BhBk8q6z//pFqFhMRW75a30MgVsZ0ZSTKti8GAxpWsA4PNnPv6iHFpneacE6hFIqcjsz uJPQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=QyEPDAytTEl0uopebdyNHFfe+27dQnLC51NhV3dnBlQ=; b=lpAwqzNOLRW5u8Y5EKsnbToNO0CTK1o8tKRJKHJLPt5g+wlqByLcguPANJ4i2+cAAV z8A4vEy5cOderVRIIYQ0EJ+xi6CHkmWyyVoRXy5sIuT74z4SkDh+YIu7XeERM88DCB7C NR/w56SaYfmckYkIrNcfeqlQThvdrF6j1IH0PQR+aCYTAgN1qArfQwoPzuofX+INkN6E esEGmUoN9bqY8agUbDa68ZQb1HVycjlfY0Io1iyuyUHuMJ6D4N4aqCmyBC2pIrwTGrQv wNXRDtgz4iKSav4aHE4QxcmbHp3Jg9lbIrzJBrKuL9pVBbcN7OnBOtmmXtkAxqo6N8YA 7dsA== X-Gm-Message-State: AOAM532hLAMcnto7vaARdLL0k9J7YKLkMW5/Rtzt2adc4Z2LmZar8rc2 qIy2S5jEq0MtTGKDbzmhp4dF/A== X-Google-Smtp-Source: ABdhPJz8UN2fY5APc9Sjo+vvBdGu2jQKXfD20JyDILa/0y1RXXAbuPmiCHQzcqnjlgbJWrFl1+onVg== X-Received: by 2002:a6b:3118:: with SMTP id j24mr3303413ioa.171.1606938280197; Wed, 02 Dec 2020 11:44:40 -0800 (PST) Received: from [192.168.1.30] ([65.144.74.34]) by smtp.gmail.com with ESMTPSA id z18sm1157219ilb.26.2020.12.02.11.44.39 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 02 Dec 2020 11:44:39 -0800 (PST) Subject: Re: [PATCH] blk-throttle: don't check whether or not lower limit is valid if CONFIG_BLK_DEV_THROTTLING_LOW is off To: Yu Kuai , tj@kernel.org Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yi.zhang@huawei.com, zhangxiaoxu5@huawei.com References: <20201126031834.40807-1-yukuai3@huawei.com> From: Jens Axboe Message-ID: <51844d83-3447-cf0f-bde2-d368f5f43f5a@kernel.dk> Date: Wed, 2 Dec 2020 12:44:38 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201126031834.40807-1-yukuai3@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/25/20 8:18 PM, Yu Kuai wrote: > blk_throtl_update_limit_valid() will search for descendants to see if > 'LIMIT_LOW' of bps/iops and READ/WRITE is nonzero. However, they're always > zero if CONFIG_BLK_DEV_THROTTLING_LOW is not set, furthermore, a lot of > time will be wasted to iterate descendants. > > Thus do nothing in blk_throtl_update_limit_valid() in such situation. Applied, thanks. -- Jens Axboe