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=-0.9 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED 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 0B120C43142 for ; Mon, 30 Jul 2018 18:58:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A820920870 for ; Mon, 30 Jul 2018 18:58:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="J/LuEUIC"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="nEC124Go" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A820920870 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=codeaurora.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 S1731589AbeG3UfA (ORCPT ); Mon, 30 Jul 2018 16:35:00 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:34968 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729542AbeG3Ue7 (ORCPT ); Mon, 30 Jul 2018 16:34:59 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 939B0605BD; Mon, 30 Jul 2018 18:58:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1532977117; bh=8/MjThK2c5ABUIfk7l9QOY+sdXH2IMiB6GT1iSQJJJM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=J/LuEUICBgr1N7daxw7OwVyGkTT4087QBCkq63RvjzhGx5o+VCdoScFv/YKvcz8aV ur76S+KUJOwacI0WFAiq+n/W2dtgTVPdWPk+/5jL2YNyNaMdIdXTAXZc0nxsjyXP+f d4jPITGQWJh0eg+6Azupfp3X10czPof3oyzPaoL8= Received: from mail.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id AE03F60117; Mon, 30 Jul 2018 18:58:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1532977116; bh=8/MjThK2c5ABUIfk7l9QOY+sdXH2IMiB6GT1iSQJJJM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=nEC124Gohu3WhQaKb1aVoTkJB+TmxJMk3dwI2ssSHqgRxmXbFLOHTz1jiaMGsiznc eMhEs0Ti6WqOMPYupbKyw/MzDoU/aeM8uEW51A1J3nJgypQEBO12G8rBSfVV587ybk ZeqcqTP+7csaiuGxnxgoSKzLHHk9/v6GNfeFTjsg= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 30 Jul 2018 11:58:36 -0700 From: skannan@codeaurora.org To: "Rafael J. Wysocki" Cc: MyungJoo Ham , Kyungmin Park , Chanwoo Choi , Rob Herring , Mark Rutland , Linux PM , devicetree@vger.kernel.org, Linux Kernel Mailing List , rjwysocki@gmail.com Subject: Re: [PATCH] PM / devfreq: Generic cpufreq governor In-Reply-To: References: <1532750217-8886-1-git-send-email-skannan@codeaurora.org> Message-ID: <534629d03437bc8e72a62d89e726dbe5@codeaurora.org> X-Sender: skannan@codeaurora.org User-Agent: Roundcube Webmail/1.2.5 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-07-29 03:52, Rafael J. Wysocki wrote: > On Sat, Jul 28, 2018 at 5:56 AM, Saravana Kannan > wrote: >> Many CPU architectures have caches that can scale independent of the >> CPUs. >> Frequency scaling of the caches is necessary to make sure the cache is >> not >> a performance bottleneck that leads to poor performance and power. The >> same >> idea applies for RAM/DDR. >> >> To achieve this, this patch adds a generic devfreq governor that can >> listen >> to the frequency transitions of each CPU frequency domain and then >> adjusts >> the frequency of the cache (or any devfreq device) based on the >> frequency >> of the CPUs. >> >> To decide the frequency of the device, the governor does one of the >> following: >> >> * Uses a CPU frequency to device frequency mapping table >> - Either one mapping table used for all CPU freq policies (typically >> used >> for system with homogeneous cores/clusters that have the same >> OPPs. >> - One mapping table per CPU freq policy (typically used for ASMP >> systems >> with heterogeneous CPUs with different OPPs) >> >> OR >> >> * Scales the device frequency in proportion to the CPU frequency. So, >> if >> the CPUs are running at their max frequency, the device runs at its >> max >> frequency. If the CPUs are running at their min frequency, the >> device >> runs at its min frequency. And interpolated for frequencies in >> between. > > While not having looked at the details of the patch yet, I would > change the name of the feature to "Generic cpufreq transition > governor" to make it somewhat less ambiguous. In my opinion it makes it look MORE like this is a cpufreq governor. How about the following? PM / devfreq: Generic cpufreq to devfreq mapping governor Seem a lot more clear to me. I'm open to suggestions for the devfreq governor name too. "cpufreq" has been very confusing so far. cpufreq-map maybe? Thanks, Saravana