From patchwork Wed May 18 12:53:40 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shilpasri G Bhat X-Patchwork-Id: 9118771 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id E8E039F1D3 for ; Wed, 18 May 2016 12:54:34 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1ED5C201FE for ; Wed, 18 May 2016 12:54:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 280352021F for ; Wed, 18 May 2016 12:54:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752864AbcERMyI (ORCPT ); Wed, 18 May 2016 08:54:08 -0400 Received: from e28smtp07.in.ibm.com ([125.16.236.7]:46755 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752839AbcERMyG (ORCPT ); Wed, 18 May 2016 08:54:06 -0400 Received: from localhost by e28smtp07.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 18 May 2016 18:24:01 +0530 X-IBM-Helo: d28dlp03.in.ibm.com X-IBM-MailFrom: shilpa.bhat@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org;linux-pm@vger.kernel.org Received: from d28relay08.in.ibm.com (d28relay08.in.ibm.com [9.184.220.159]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 90280125804F; Wed, 18 May 2016 18:26:13 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay08.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u4ICs0Jd21889194; Wed, 18 May 2016 18:24:00 +0530 Received: from d28av02.in.ibm.com (localhost [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u4ICrwVp011479; Wed, 18 May 2016 18:24:00 +0530 Received: from localhost.in.ibm.com ([9.124.35.24]) by d28av02.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u4ICrrsp011323; Wed, 18 May 2016 18:23:58 +0530 From: Shilpasri G Bhat To: rjw@rjwysocki.net Cc: viresh.kumar@linaro.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, ego@linux.vnet.ibm.com, shreyas@linux.vnet.ibm.com, akshay.adiga@linux.vnet.ibm.com, linuxppc-dev@ozlabs.org, Shilpasri G Bhat Subject: [RFC PATCH] cpufreq: powernv: Add fast_switch callback Date: Wed, 18 May 2016 18:23:40 +0530 Message-Id: <1463576020-18597-2-git-send-email-shilpa.bhat@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1463576020-18597-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> References: <1463576020-18597-1-git-send-email-shilpa.bhat@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16051812-0025-0000-0000-00000C5A3E2D X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-8.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add fast_switch driver callback to support frequency update in interrupt context while using schedutil governor. Changing frequency in interrupt context will remove the jitter on the workloads which can be seen when a kworker thread is used for the changing the frequency. Signed-off-by: Shilpasri G Bhat --- drivers/cpufreq/powernv-cpufreq.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c index 54c4536..4553eb6 100644 --- a/drivers/cpufreq/powernv-cpufreq.c +++ b/drivers/cpufreq/powernv-cpufreq.c @@ -678,6 +678,8 @@ static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy) for (i = 0; i < threads_per_core; i++) cpumask_set_cpu(base + i, policy->cpus); + policy->fast_switch_possible = true; + kn = kernfs_find_and_get(policy->kobj.sd, throttle_attr_grp.name); if (!kn) { int ret; @@ -854,6 +856,24 @@ static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy) del_timer_sync(&gpstates->timer); } +static unsigned int powernv_fast_switch(struct cpufreq_policy *policy, + unsigned int target_freq) +{ + int index; + struct powernv_smp_call_data freq_data; + + cpufreq_frequency_table_target(policy, policy->freq_table, + target_freq, + CPUFREQ_RELATION_C, &index); + if (index < 0 || index >= powernv_pstate_info.nr_pstates) + return CPUFREQ_ENTRY_INVALID; + freq_data.pstate_id = powernv_freqs[index].driver_data; + freq_data.gpstate_id = powernv_freqs[index].driver_data; + set_pstate(&freq_data); + + return pstate_id_to_freq(-index); +} + static struct cpufreq_driver powernv_cpufreq_driver = { .name = "powernv-cpufreq", .flags = CPUFREQ_CONST_LOOPS, @@ -861,6 +881,7 @@ static struct cpufreq_driver powernv_cpufreq_driver = { .exit = powernv_cpufreq_cpu_exit, .verify = cpufreq_generic_frequency_table_verify, .target_index = powernv_cpufreq_target_index, + .fast_switch = powernv_fast_switch, .get = powernv_cpufreq_get, .stop_cpu = powernv_cpufreq_stop_cpu, .attr = powernv_cpu_freq_attr,