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,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 4BD1AC433DB for ; Fri, 19 Feb 2021 05:00:43 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9E78F64D9F for ; Fri, 19 Feb 2021 05:00:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9E78F64D9F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/W0LjYE4pdheIn5QKYiijJxZOi4BYyx4vJhQUBxnayc=; b=hPv6BPisLiimxUCwkTs1knUU2 mE5cBpO9NWGzcnUnpgMPBAeaTexHq8B9othoqT+IFeCmTX8HWLxxrepdzuXHLrbRzVbV/CaS4jDIr +cuaLHKXskuOV0kSF0LR8ME4nuqjzkNDaazJhZ7KF0FFKtolLlg/BuSNOgxPKrS7rlYic68ZhFntp bjntUtLqCIXUBaDbuOh02k6Pt/MVilq3CvkzlKKUtFH7GBaZqnS5H6shsER6mrjicxv7PRHbxfb0o YIdacaPFksC65qFZ0hMu9IwDURQt3eC5sDatik1DVqeULH9eCA4SUfAujXLU8p6T8/ma/H5FIpn+M 2PJM/KYZg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lCxs8-0004Bk-VD; Fri, 19 Feb 2021 04:58:32 +0000 Received: from mail-pf1-x42f.google.com ([2607:f8b0:4864:20::42f]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1lCxs4-0004B9-Vo for linux-arm-kernel@lists.infradead.org; Fri, 19 Feb 2021 04:58:30 +0000 Received: by mail-pf1-x42f.google.com with SMTP id y25so3081517pfp.5 for ; Thu, 18 Feb 2021 20:58:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=VQ8JfAUf/ySg/ATklOLfVi6FRg+WrMTayYjOprp1Sx0=; b=zrt/i2IK+MNx8nousJ5vhUkJhPOg+W4lAaza3KU7WU5akL9GwRYl6fQtYhNv5OPgY+ DH+LAVbb4FtDeXzzY815wVASFyQv3PCGNAStQH0V4uw8EBNU1Ir8Hsl/6tzswvd1TC8c cU0qPNlAxe9fwZ4gRAFODY1w66JGzR3S+RYHoonlLtQt9BbnkLkdx8RBgxU2LTn/utZb /YDLg1RG0yahHSXebbwpRlOJdhqjI14F0xjzasUbv7hvqKPJm2vwlVBm6T1JMwWWT2N9 NkJkVQb6OtohZ1RPApNY6L7wwiT0oR+nP9JDUape8vht0cXFLole/ud9E1+fq/+LyGZP fUgg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=VQ8JfAUf/ySg/ATklOLfVi6FRg+WrMTayYjOprp1Sx0=; b=PeTFIORbaJ2wmkkxiAhVICF87ML5mOvsHNzz1qRDgnHvH99qS3e5hP0DEMBSTE6INy ypVduGnZanMm4zaz/3TPRsZZzlNW96uig3a1mfRxgREhup5YlbEnJdWZLcViTza3NrHb Fd08Pcn3aHycFS3Nk/ABLfR6dmu185Sd5vz/zKGASGu8QcZ/q2iJ7+wAQ2FEXGVzF4uw 49UNQksW0JVbsB+qzpBBRbFusjgpPV/jVz4eZFN4dRk1Mgzjrxhph3ssUWBMw4w94vFp HNyYHhEgIt3gU8UYQWTCi/JuTzLbHPtWU+NGwdGroLrsoBCZD0yLFp/1GQVsai5LnJVJ LO3g== X-Gm-Message-State: AOAM532lcaphqza/BmyZkHg8ozXMK9gzrqUYLJLNEJRBLzyxog66gBpR 9rdJTjjWH7+Gx71xLGDrYPmrEw== X-Google-Smtp-Source: ABdhPJwu4+l3z0J6l2dIbzGBCfMCuNcRbcfi8xlFg/zWmBVxwfBMR2E2oxOYuMXfJN2cC8DQBRZXAg== X-Received: by 2002:a63:1845:: with SMTP id 5mr7015563pgy.244.1613710706075; Thu, 18 Feb 2021 20:58:26 -0800 (PST) Received: from localhost ([122.172.59.240]) by smtp.gmail.com with ESMTPSA id s18sm7433890pfm.129.2021.02.18.20.58.25 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 18 Feb 2021 20:58:25 -0800 (PST) Date: Fri, 19 Feb 2021 10:28:23 +0530 From: Viresh Kumar To: Ionela Voinescu Subject: Re: [PATCH V3 1/2] topology: Allow multiple entities to provide sched_freq_tick() callback Message-ID: <20210219045823.beeijwaymd63prk7@vireshk-i7> References: <20210203114521.GA6380@arm.com> <20210205091424.3od3tme3f7mh7ebp@vireshk-i7> <20210217002422.GA17422@arm.com> <20210218093304.3mt3o7kbeymn5ofl@vireshk-i7> <20210218163635.GA23622@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210218163635.GA23622@arm.com> User-Agent: NeoMutt/20180716-391-311a52 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210218_235829_385896_73239941 X-CRM114-Status: GOOD ( 16.46 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Vincent Guittot , linux-pm@vger.kernel.org, Catalin Marinas , Rafael Wysocki , linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Sudeep Holla , Will Deacon , linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 18-02-21, 16:36, Ionela Voinescu wrote: > Yes, we don't care if there is no cpufreq driver, as the use of AMUs won't > get initialised either. But we do care if there is a cpufreq driver that > does not support frequency invariance, which is the example above. > > The intention with the patches that made cpufreq based invariance generic > a while back was for it to be present, seamlessly, for as many drivers as > possible, as a less than accurate invariance default method is still > better than nothing. Right. > So only a few drivers today don't support cpufreq based FI Only two AFAICT, both x86, and the AMU stuff doesn't conflict with them. drivers/cpufreq/intel_pstate.c drivers/cpufreq/longrun.c > but it's not a guarantee that it will stay this way. What do you mean by "no guarantee" here ? The very core routines (cpufreq_freq_transition_end() and cpufreq_driver_fast_switch()) of the cpufreq core call arch_set_freq_scale() today and this isn't going to change anytime soon. If something gets changed there someone will need to see other parts of the kernel which may get broken with that. I don't see any need of complicating other parts of the kernel like, amu or cppc code for that. They should be kept simple and they should assume cpufreq invariance will be supported as it is today. -- viresh _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel