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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,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 B1AEDC3A59F for ; Thu, 29 Aug 2019 15:46:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84DCD2166E for ; Thu, 29 Aug 2019 15:46:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567093574; bh=K1DC5a8M0SmiDc8LclIbau54Wi3kHL5WsQYED1zUqlY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ybWWxJf/E9ktHaD0luXxBsp9TYxkGqljpgSSlea8KGHOo8DHqZhU3+2lWCIryMe7k HIxBX1awiOBfg9rdfPMv3QrW1u51fWDyOyxK94GzBDfgTW0BQfu5ultk07TnPZJMln Yz8ap75exhAJb926sbqL/Rwq/9OmAFx0Hx8eetTI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726518AbfH2PqN (ORCPT ); Thu, 29 Aug 2019 11:46:13 -0400 Received: from mail-qt1-f194.google.com ([209.85.160.194]:38573 "EHLO mail-qt1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726283AbfH2PqN (ORCPT ); Thu, 29 Aug 2019 11:46:13 -0400 Received: by mail-qt1-f194.google.com with SMTP id b2so695561qtq.5; Thu, 29 Aug 2019 08:46:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=aegqxwkNQfcl+Wg+uXNzhfA96N2TVnZEqWU/pVTp7O0=; b=SYTOMOQY9y4DHxazFL0VJ5Esl3I6kjkjeY0wH2mN1HPH/S+CJKwCkJ9ApmUWzpIltd 7mJTwhspOUW+Xq1yyt6HsCav03dKy3i8mHcOeUt+mYUBpY0Scdy6du0IdP5UGhKYWKR4 uO9gCZM6CksSTlpE/JECpZ/UtrIVw4ggrkWHKzVoykbTt3IfBI/zajFxcXk5E/VTWwHz RHQBykyBHBb/8qCtJR6BCiUAf21PHnWpn6uGQvPH2tRR/eEiZQhk+FPlqF/+32rRDSgD WwxUJYxcBZ4ZLQbdgQJDNQyHCJ1vtyy7JdkUZ9bxQdOZd2BI7CS43lRjQqsx224uAh4h F56w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=aegqxwkNQfcl+Wg+uXNzhfA96N2TVnZEqWU/pVTp7O0=; b=RzGAA9/t1uy9W4FmUE7fpNbp6L0B8Eg8hCEz85gcX1y52xNxBoVj52j2faeNuNRkIp izC/Ey/quYQ2emuYsRvPm9tw5Enwk1hVCNsyu1P88UVlLl5FQaLiSEXTjjvmRSsbyMcd 384vF/LKyNHiFmcs+bR4ipVC5C4orTGtuFd40ENaTUBQ/A0+Wdnu48B2bok5dcF8g9TF HJwwipEEpb0YWgb4RtwqrcvuqGZGR7kHzut0VCsjC3Q0cDvUg6+L1fuuV71mCDqQ6v1o rNb+QKwepDjnde0wE0gyR9NfIs8NDKz5w6ipMYdMEuldBSOg6HiSyR4TJ4PXMbzrvfxm pk2g== X-Gm-Message-State: APjAAAUzyTH1bW73y1+fP+R3gi+gwiZdGAXUuGx2UfCY1A+lsErj7Sbm vXJR8NFW27jXttfHcld/28k= X-Google-Smtp-Source: APXvYqzjcJkE7617DYDqIr3PG4ZNC8XGG7HEcgfFWkDmRvAS0Ibl+uE1pNYw7GOE8LHelm+6jWMe2A== X-Received: by 2002:ac8:3449:: with SMTP id v9mr10473377qtb.163.1567093572550; Thu, 29 Aug 2019 08:46:12 -0700 (PDT) Received: from localhost ([2620:10d:c091:500::1:7e32]) by smtp.gmail.com with ESMTPSA id k11sm1194357qtp.26.2019.08.29.08.46.10 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 29 Aug 2019 08:46:10 -0700 (PDT) Date: Thu, 29 Aug 2019 08:46:09 -0700 From: Tejun Heo To: Hillf Danton Cc: axboe@kernel.dk, newella@fb.com, clm@fb.com, josef@toxicpanda.com, dennisz@fb.com, lizefan@huawei.com, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, kernel-team@fb.com, cgroups@vger.kernel.org, Josef Bacik , Rik van Riel Subject: Re: [PATCH 08/10] blkcg: implement blk-iocost Message-ID: <20190829154609.GU2263813@devbig004.ftw2.facebook.com> References: <20190828220600.2527417-1-tj@kernel.org> <20190829133928.16192-1-hdanton@sina.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190829133928.16192-1-hdanton@sina.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hello, On Thu, Aug 29, 2019 at 09:39:28PM +0800, Hillf Danton wrote: > > + on_q_ns = ktime_get_ns() - rq->alloc_time_ns; > > + rq_wait_ns = rq->start_time_ns - rq->alloc_time_ns; > > + > ehm... alloc_time makes no sense wrt start_time if this is their only > use. What are you trying to measure with the two stamps if they are > meaningfully apart? Queue depth depletion. > > + rq_qos_add(q, rqos); > > + ret = blkcg_activate_policy(q, &blkcg_policy_iocost); > > + if (ret) { > > + rq_qos_del(q, rqos); > > free_percpu(ioc->pcpu_stat); Good catch. Will send a follow up patch. Thanks. -- tejun