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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 80893C433E2 for ; Thu, 3 Sep 2020 11:15:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F7AC2065F for ; Thu, 3 Sep 2020 11:15:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XHOo/wjg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728407AbgICLPo (ORCPT ); Thu, 3 Sep 2020 07:15:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728422AbgICLOa (ORCPT ); Thu, 3 Sep 2020 07:14:30 -0400 Received: from mail-wr1-x441.google.com (mail-wr1-x441.google.com [IPv6:2a00:1450:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 506DFC061244; Thu, 3 Sep 2020 04:00:35 -0700 (PDT) Received: by mail-wr1-x441.google.com with SMTP id m6so2767866wrn.0; Thu, 03 Sep 2020 04:00:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:references:in-reply-to:subject:date:message-id :mime-version:content-transfer-encoding:thread-index :content-language; bh=SE22zCSVEAoxI5J9vYZxU5jk2PTxW8rlRt79/vsQVMc=; b=XHOo/wjgMIAcFXOEpJ8LD3JeyIS06RbRzdhJHQUNQryAsL5MqI9KCGWsJDlWGw6Hww 0r1qNVory+ouhS3YefBZ3bC51Wemkyd5AZ/T2v3yonZYSLyRjebFpnAJaRXEFjXiWSK/ DUUTknp8LIhWqVy8rhgEG9QW/cAssbuWgMFTs1OW7xUnSOUXWh1vBvG4/utmhUmshssd ZolOYsiKduKgb0bRlz0wzBCTQfC/r6haJPeN3CvbPf70QjElIk39PqgeTz7KA4Ts2JVK 7t/MN3sATXo6IDk0wOjGSMRLimJGPLXCz3gIfStJcaNtRUWwumRdA8PcXB/BBbd6Devf o0Mw== 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:references:in-reply-to:subject:date :message-id:mime-version:content-transfer-encoding:thread-index :content-language; bh=SE22zCSVEAoxI5J9vYZxU5jk2PTxW8rlRt79/vsQVMc=; b=QTgzdgoYHeT45eXk00gc8Bc4McewHo3odEFQSSeUJ59oYewiSQfrCgkNJ4hvgPFuff C4uPqc6vlpFGWpux7uN700of+KA1UoW7IBdPaloyxi12K/e5UGmvrIoo3yteHVLFEzfD 9Oz8SrYHosODRAKCatImudy9W5MwZX+K+ayu7HBc7NIMTzMR9+AK+R2YQ6qmFLoH8AIR HmUYSWUcwvcp3/ap+iCp2tfVNPxihflKV4Bn0/zp5dfAvC0xXKqznatWudos8aMLoTQ5 USgFvd01UnssCMgOr+ay/4trHbRR8vsNr00GP77ofmr+lI031xmj56wTaV8+ovLsU62Z PBGg== X-Gm-Message-State: AOAM5314cMMjEe/AAPItmX83AERq3F8O1MXHhU0QJE8LX2RcTxD5NZgN IaHmu2sQNujaRfmal91xAGXnnSKkHuxTyg== X-Google-Smtp-Source: ABdhPJzT2JR3cqHJJ+PeIDEiZWnus85LDjLyqQxGZLcJGgQ0N86n6iNc76LXufOFcTVgGQkidXI/BA== X-Received: by 2002:adf:e7ce:: with SMTP id e14mr1741534wrn.43.1599130833155; Thu, 03 Sep 2020 04:00:33 -0700 (PDT) Received: from AnsuelXPS ([5.170.166.111]) by smtp.gmail.com with ESMTPSA id s5sm3876136wrm.33.2020.09.03.04.00.31 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 03 Sep 2020 04:00:32 -0700 (PDT) From: To: "'Sibi Sankar'" , "'Viresh Kumar'" Cc: , , "'Sudeep Holla'" , "'Rafael J. Wysocki'" , "'Rob Herring'" , , , References: <20200821140026.19643-1-ansuelsmth@gmail.com> <20200824104053.kpjpwzl2iw3lpg2m@vireshk-i7> <039d01d67f6a$188700d0$49950270$@gmail.com> <20200903065314.y3ynhwydahaeg6o6@vireshk-i7> <6dc62d231c776b2cdfdc36cfe36e4140@codeaurora.org> In-Reply-To: <6dc62d231c776b2cdfdc36cfe36e4140@codeaurora.org> Subject: R: R: [RFC PATCH v3 0/2] Add Krait Cache Scaling support Date: Thu, 3 Sep 2020 13:00:27 +0200 Message-ID: <01f201d681e1$70ff1bc0$52fd5340$@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable X-Mailer: Microsoft Outlook 16.0 Thread-Index: AQHE1KUT8lrzCHz2sVzN5qwVSE5wCwFurxwcAoW98xABeMrvawKX8ba/Aay9QdupLIiWEA== Content-Language: it Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Messaggio originale----- > Da: sibis=3Dcodeaurora.org@mg.codeaurora.org > Per conto di Sibi Sankar > Inviato: gioved=EC 3 settembre 2020 09:13 > A: Viresh Kumar > Cc: ansuelsmth@gmail.com; vincent.guittot@linaro.org; > saravanak@google.com; 'Sudeep Holla' ; 'Rafael = J. > Wysocki' ; 'Rob Herring' ; = linux- > pm@vger.kernel.org; devicetree@vger.kernel.org; linux- > kernel@vger.kernel.org > Oggetto: Re: R: [RFC PATCH v3 0/2] Add Krait Cache Scaling support >=20 > On 2020-09-03 12:23, Viresh Kumar wrote: > > On 31-08-20, 09:41, ansuelsmth@gmail.com wrote: > >> On 31-08-20, Sibi wrote: > >> > On 2020-08-24 16:10, Viresh Kumar wrote: > >> > > +Vincent/Saravana/Sibi > >> > > > >> > > On 21-08-20, 16:00, Ansuel Smith wrote: > >> > >> This adds Krait Cache scaling support using the cpufreq = notifier. > >> > >> I have some doubt about where this should be actually placed = (clk > or > >> > >> cpufreq)? > >> > >> Also the original idea was to create a dedicated cpufreq = driver (like > >> > >> it's done in > >> > >> the codeaurora qcom repo) by copying the cpufreq-dt driver and > adding > >> > >> the cache > >> > >> scaling logic but i still don't know what is better. Have a = very > >> > >> similar driver or > >> > >> add a dedicated driver only for the cache using the cpufreq notifier > >> > >> and do the > >> > >> scale on every freq transition. > >> > >> Thanks to everyone who will review or answer these questions. > >> > > > >> > > Saravana was doing something with devfreq to solve such issues = if I > >> > > wasn't mistaken. > >> > > > >> > > Sibi ? > >> > > >> > IIRC the final plan was to create a devfreq device > >> > and devfreq-cpufreq based governor to scale them, this > >> > way one can switch to a different governor if required. > >> > >> So in this case I should convert this patch to a devfreq driver- > > > > I think this should happen nevertheless. You are doing DVFS for a > > device which isn't a CPU and devfreq looks to be the right place of > > doing so. > > > >> Isn't overkill to use a governor for such a task? > >> (3 range based on the cpufreq?) > > > > I am not sure about the governor part here, maybe it won't be = required > > ? >=20 > Yeah I don't see it being needed in ^^ > case as well. I just mentioned them as > an advantage in case you wanted to switch > to a different governor in the future. >=20 > https://lore.kernel.org/lkml/d0bc8877-6d41-f54e-1c4c- > 2fadbb9dcd0b@samsung.com/ >=20 > A devfreq governor tracking cpufreq was > generally accepted but using a cpufreq > notifier to achieve that was discouraged. >=20 I read the patch discussion and it looks like at the very end they lost interest in pushing it. That would very fit what I need here so I'm asking how should I proceed? Keep the cpufreq notifier? Introduce a dedicated governor? Ask them to resume the pushing or try to include the changes to the passive governor by myself?=20 > -- > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, > a Linux Foundation Collaborative Project.