From patchwork Tue Oct 24 10:27:16 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dietmar Eggemann X-Patchwork-Id: 116936 Delivered-To: patch@linaro.org Received: by 10.140.22.164 with SMTP id 33csp5635821qgn; Tue, 24 Oct 2017 03:27:31 -0700 (PDT) X-Google-Smtp-Source: ABhQp+SOGNqbpqRBCZjvvo5ny042c/ztreqoLnWE19sqtIdQEcR/PoMTIbhhzdFGolP4Bk2Q4Jze X-Received: by 10.84.233.131 with SMTP id l3mr12534304plk.448.1508840851506; Tue, 24 Oct 2017 03:27:31 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1508840851; cv=none; d=google.com; s=arc-20160816; b=nzri3CubU9ldXYNe6flr/o1WfPnjwOWR/18IvYorqBzXwxY5rMSmQpkqlNIu7sPnaY N3yhdZ3yNU5SgYpSWJFwtd4zsi3MyltQQScfp/e0iXsGHaCeXtLtL1RpIUsoe31YPYPp VzKtlj/0mWox1/LDOaGn1bRdBE4lKAdGvhqk5mdABs1LKgIJn2riJYqW5uFRNLFwa7WG 5cFxdhsLfoFE+Xx9I183iUm7gcd93wZKerjxiw+rwizReJJdI72e8Q8iQOm5NPz7bIoj 24Lkv8Fxd0o9H5Uk5CWnfkZ7k0MeIxnqQGHE0FqozeYjUYduKN7v0IRTIQ1d8q1PZ+R0 dj3A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:message-id:date:subject:cc:to:from :arc-authentication-results; bh=0yvBWfHTTeAGS1F5TyQK79z997/l2sl5UXmOi8lepog=; b=K0QE0WlYyoVRGmALFW8HSMUc25463jg0wBllWT+m+ehd4FcZ5v0BpIkbpOEPAOiEg5 bV4XDTpB1F1KwgOiWz/FvxkMJNBcMdloFxR+sY7UBte4j2FuEeaebxRh4xu+f7AS/9Rc ENg1hu227UH8HwZ3cu5heO8JleZTU5e/Vpn7BgvTwg+gaVq5qDR/hbL2OdqpvWfZwoNF bvwDqMl1dzbltoUeMZe+b+88liWztnOCNq0DDqKgVWeNpaejDWgliRcTiVMYmOVKDJet amqfpaG9yV9wbKJoAnRF8KmOnuleRs9ZYFpIsKJHuir63yxgFnvPuQstwRSw2ONN+Gll Uxdg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id t3si5224596plz.536.2017.10.24.03.27.31; Tue, 24 Oct 2017 03:27:31 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932601AbdJXK13 (ORCPT + 27 others); Tue, 24 Oct 2017 06:27:29 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:53120 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932306AbdJXK10 (ORCPT ); Tue, 24 Oct 2017 06:27:26 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9C3F380D; Tue, 24 Oct 2017 03:27:26 -0700 (PDT) Received: from e107985-lin.cambridge.arm.com (e107985-lin.cambridge.arm.com [10.1.210.41]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 8CD763F25D; Tue, 24 Oct 2017 03:27:25 -0700 (PDT) From: Dietmar Eggemann To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Russell King , Vincent Guittot , Juri Lelli Subject: [PATCH v3 0/2] arm: remove cpu_efficiency Date: Tue, 24 Oct 2017 11:27:16 +0100 Message-Id: <20171024102718.16113-1-dietmar.eggemann@arm.com> X-Mailer: git-send-email 2.11.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org v2: review results [1]: Vincent pointed out that there are missing of_node_put() calls for cpu device node in parse_dt_topology(). Added them with an extra patch. v1: review results [2]: Vincent pointed out that there is a superfluous continue statement in parse_dt_topology(). Got rid of it. Krzysztof Kozlowski took the exynos and Simon Horman the renesas related dt bits into their for-next (v4.15) branches. *** For Cortex-A15/A7 arm big.LITTLE systems there are currently two ways to set the cpu capacity. The first one (commit 06073ee26775 "ARM: 8621/3: parse cpu capacity-dmips-mhz from DT") is based on dt 'cpu capacity-dmips-mhz' bindings and the appropriate dt parsing code in drivers/base/arch_topology.c. It further takes differences in maximum cpu frequency values into consideration, normalizes the maximum cpu capacity to SCHED_CAPACITY_SCALE (1024) and scales all the cpus accordingly. cpu capacity = (capacity-dmips-mhz * max cpu frequency) / (max capacity-dmips-mhz * max (max cpu frequency) This solution is shared between arm and arm64 and works for other combinations of big and little cpus (besides Cortex-A15/A7) as well. The second one (commit 339ca09d7ada "ARM: 7463/1: topology: Update cpu_power according to DT information" is based on the 'struct cpu_efficiency table_efficiency[]' and the dt parsing code in arch/arm/kernel/topology.c. It further requires a clock-frequency property per cpu node, calculates a so called middle frequency for an average cpu in the system which is as close as possible to SCHED_CAPACITY_SCALE (1024) and uses this to compute the cpu capacity values. cpu capacity = (cpu efficiency * clock frequency) / middle capacity This solution only works for Cortex-A15/A7 arm big.LITTLE systems. The aim of this patch is to have only one solution for all arm and arm64 big.LITTLE platforms. (1) Therefore, it removes the code for the 'cpu_efficiency/ clock-frequency dt property' (second) solution. (2) Moreover, it will also assure that the highest original cpu capacity (rq->cpu_capacity_orig) in a non-smt system is SCHED_CAPACITY_SCALE (1024). (3) And finally, another advantage is the dynamic detection of the max cpu frequency which comes with the first solution instead of the static clock-frequency dt property value. Currently, the arm dt parsing code in parse_dt_topology() checks if the dt uses the capacity-dmips-mhz property. If this is the case it uses the first, otherwise the second solution. This patch removes the code for the second solution from arch/arm/kernel/topology.c. With the dt related patches for exynos and renesas now in the appropriated for-next branches for v4.15 there are no Cortex-A15/A7 arm big.LITTLE systems left relying on the 'cpu_efficiency/clock-frequency dt property' based solution anymore. This patch has been tested on TC2 and Samsung Chromebook 2 13" (peach-pi, Exynos 5800). [1] https://marc.info/?l=linux-kernel&m=150781686132670&w=2 [2] https://marc.info/?l=linux-kernel&m=150410411807050&w=2 Changes v2->v3: - Rebase on top of v4.14-rc6 - Added missing of_node_put() for cpu device node [02/02] Changes v1->v2: - Rebase on top of v4.14-rc4 - Remove superfluous continue statement in parse_dt_topology() [01/04] - Remove 'cpu capacity scale management' and 'cpu capacity table' related comments [01/04] - Remove dt related patches [02-04/04] Dietmar Eggemann (2): arm: topology: remove cpu_efficiency arm: topology: add missing of_node_put() for cpu device node arch/arm/kernel/topology.c | 135 ++------------------------------------------- 1 file changed, 6 insertions(+), 129 deletions(-) -- 2.11.0