From patchwork Thu Jul 27 19:33:07 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dietmar Eggemann X-Patchwork-Id: 9867497 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id ECFD760382 for ; Thu, 27 Jul 2017 19:35:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E03322884B for ; Thu, 27 Jul 2017 19:35:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D454B2886C; Thu, 27 Jul 2017 19:35:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4498B2884B for ; Thu, 27 Jul 2017 19:35:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751801AbdG0Tdy (ORCPT ); Thu, 27 Jul 2017 15:33:54 -0400 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:51100 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751788AbdG0Tdu (ORCPT ); Thu, 27 Jul 2017 15:33:50 -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 B45F0164F; Thu, 27 Jul 2017 12:33:49 -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 7B27F3F540; Thu, 27 Jul 2017 12:33:47 -0700 (PDT) From: Dietmar Eggemann To: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org, linux@arm.linux.org.uk, Greg Kroah-Hartman , Russell King , Catalin Marinas , Will Deacon , Juri Lelli , Vincent Guittot , Peter Zijlstra , Morten Rasmussen , Viresh Kumar , "Rafael J . Wysocki" , Sudeep Holla Subject: [PATCH v3 05/10] drivers base/arch_topology: provide frequency-invariant accounting support Date: Thu, 27 Jul 2017 20:33:07 +0100 Message-Id: <20170727193312.9849-6-dietmar.eggemann@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170727193312.9849-1-dietmar.eggemann@arm.com> References: <20170727193312.9849-1-dietmar.eggemann@arm.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Implements the arch-specific (arm and arm64) frequency-invariance setter function arch_set_freq_scale() which provides the following frequency scaling factor: current_freq(cpu) << SCHED_CAPACITY_SHIFT / max_supported_freq(cpu) One possible consumer of the frequency-invariance getter function topology_get_freq_scale() is the Per-Entity Load Tracking (PELT) mechanism of the task scheduler. Allow inlining of topology_get_freq_scale() into the task scheduler fast path (e.g. __update_load_avg_se()) by coding it as a static inline function in the arch topology header file. Cc: Greg Kroah-Hartman Cc: Juri Lelli Signed-off-by: Dietmar Eggemann Acked-by: Viresh Kumar --- drivers/base/arch_topology.c | 14 ++++++++++++++ include/linux/arch_topology.h | 10 ++++++++++ 2 files changed, 24 insertions(+) diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index 562e0c93ae52..af9ab98a233e 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -22,6 +22,20 @@ #include #include +DEFINE_PER_CPU(unsigned long, freq_scale) = SCHED_CAPACITY_SCALE; + +void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq, + unsigned long max_freq) +{ + unsigned long scale; + int i; + + scale = (cur_freq << SCHED_CAPACITY_SHIFT) / max_freq; + + for_each_cpu(i, cpus) + per_cpu(freq_scale, i) = scale; +} + static DEFINE_MUTEX(cpu_scale_mutex); static DEFINE_PER_CPU(unsigned long, cpu_scale) = SCHED_CAPACITY_SCALE; diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h index 9af3c174c03a..3e3c2657c9a1 100644 --- a/include/linux/arch_topology.h +++ b/include/linux/arch_topology.h @@ -4,6 +4,8 @@ #ifndef _LINUX_ARCH_TOPOLOGY_H_ #define _LINUX_ARCH_TOPOLOGY_H_ +#include + void topology_normalize_cpu_scale(void); struct device_node; @@ -14,4 +16,12 @@ unsigned long topology_get_cpu_scale(struct sched_domain *sd, int cpu); void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity); +DECLARE_PER_CPU(unsigned long, freq_scale); + +static inline +unsigned long topology_get_freq_scale(struct sched_domain *sd, int cpu) +{ + return per_cpu(freq_scale, cpu); +} + #endif /* _LINUX_ARCH_TOPOLOGY_H_ */