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=-2.4 required=3.0 tests=DKIM_SIGNED, MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID,USER_AGENT_MUTT 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 21136C28CF6 for ; Wed, 1 Aug 2018 15:50:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD4F0208A3 for ; Wed, 1 Aug 2018 15:50:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="B05LDMxX" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD4F0208A3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389868AbeHARgV (ORCPT ); Wed, 1 Aug 2018 13:36:21 -0400 Received: from mail-yw0-f195.google.com ([209.85.161.195]:38098 "EHLO mail-yw0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389557AbeHARgV (ORCPT ); Wed, 1 Aug 2018 13:36:21 -0400 Received: by mail-yw0-f195.google.com with SMTP id r3-v6so7364614ywc.5; Wed, 01 Aug 2018 08:50:01 -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=MPNWcKhR9kEfAC1T/LYad4ecIG6j4g+V/GFDmFpdeQA=; b=B05LDMxXIIMTg0tM3cmrL4rPmASb98sMBLwg7UXNRh4eIaf0tydM9FEEQq4Aeq3kP5 ZnkT8TzLdejuXtJGnP9CDZqrCNkv9bun16l+f9rYMVzb/Rkc7veMAYlExBzqfvWsYwaq RLsiLHfRDdQ0HLxBWsi6zgNkG6cwq1yX4LJzFv+j7G1/llt8ERqSQ+M3Xq2E8t7fm8FU zMKc+3vUd/1i8e/IUob9+6aWyYsDFBnQBLYXs9JLVRH6byt2HHz9w5lFYUlf0siKgwdg 4gDC516ZNWtKKjhXLfGdDVxXCNUTOxlrZco5LzNRW8452P7UvPvujjqWPnwCw/yOyRf+ RgJg== 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=MPNWcKhR9kEfAC1T/LYad4ecIG6j4g+V/GFDmFpdeQA=; b=cyQJt8QzMqU9v8sDfxP4yOcuMpC4sAda6Cp6j+pGDgfAftE6BIdPpDCcOPiyzm7wJd T+vaCxIn5w1d+9+0kVNBN1ra8DSPp9uzExVqQ4e5yfsIhflutjbOVBQVAgs6UcZeQSZ5 GKKAm4GqNTc1EYjicDk45S+exF9SJja9nynYiXZxLDc/t6laCAfMA9W1cZi7WaxLxKX4 c+1+3B1+DkIApwWl1OcOKxyW7at5qlWSaXJVzi6ciY0Wu6qAs79AHVrq3r/vQRlp+AVV Oad4zEkGeL+YTPISxoaSg0OLOqC+iUD9FWdczlR6J5gO0cfZcvTedrBCdzGRnya+q+kl RG6A== X-Gm-Message-State: AOUpUlGM2vxxvmZ8H13tZaP/NVv+8xw8OQp/S+fXQ7hufdv8oUCgGH12 CmZwT0srdkMwcJqROuvMMRI= X-Google-Smtp-Source: AAOMgpcZAk+dr1qHvbpjPe0UAN5stzxIu8CQMiwydXAoCqLZ2TBtszgIS/MSlUf5sBFRwFJ9qWsoHw== X-Received: by 2002:a81:8:: with SMTP id 8-v6mr13714108ywa.176.1533138601030; Wed, 01 Aug 2018 08:50:01 -0700 (PDT) Received: from localhost ([2620:10d:c091:200::2:d2a6]) by smtp.gmail.com with ESMTPSA id y188-v6sm4423438ywe.2.2018.08.01.08.49.59 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 Aug 2018 08:50:00 -0700 (PDT) Date: Wed, 1 Aug 2018 08:49:58 -0700 From: Tejun Heo To: Dennis Zhou Cc: Jens Axboe , Josef Bacik , kernel-team@fb.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Johannes Weiner Subject: Re: [PATCH v2] block: make iolatency avg_lat exponentially decay Message-ID: <20180801154958.GP1206094@devbig004.ftw2.facebook.com> References: <20180801002559.36261-1-dennisszhou@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180801002559.36261-1-dennisszhou@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Tue, Jul 31, 2018 at 05:25:59PM -0700, Dennis Zhou wrote: ... > + /* > + * CALC_LOAD takes in a number stored in fixed point representation. > + * Because we are using this for IO time in ns, the values stored > + * are significantly larger than the FIXED_1 denominator (2048). > + * Therefore, rounding errors in the calculation are negligible and > + * can be ignored. > + */ > + exp_idx = min_t(int, BLKIOLATENCY_NR_EXP_FACTORS - 1, > + iolat->cur_win_nsec / BLKIOLATENCY_EXP_BUCKET_SIZE); Build bot is complaining about naked 64bit div. Should use one of the div64*() helpers. Looks good to me. Once Johannes's concerns are addressed, please feel free to add Acked-by: Tejun Heo Thanks. -- tejun