From patchwork Thu Aug 20 16:38:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 256991 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=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 A2518C433E8 for ; Thu, 20 Aug 2020 16:39:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8ADDE2054F for ; Thu, 20 Aug 2020 16:39:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729989AbgHTQjM (ORCPT ); Thu, 20 Aug 2020 12:39:12 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:41938 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728987AbgHTQjL (ORCPT ); Thu, 20 Aug 2020 12:39:11 -0400 Received: from 89-64-87-57.dynamic.chello.pl (89.64.87.57) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.459) id 48e50a6e30a2fd8e; Thu, 20 Aug 2020 18:39:06 +0200 From: "Rafael J. Wysocki" To: Linux PM Cc: Srinivas Pandruvada , LKML , Doug Smythies Subject: [PATCH 4/4] cpufreq: intel_pstate: Free memory only when turning off Date: Thu, 20 Aug 2020 18:38:40 +0200 Message-ID: <5545992.MujegtMJko@kreacher> In-Reply-To: <2283366.Lr8yYYnyev@kreacher> References: <2283366.Lr8yYYnyev@kreacher> MIME-Version: 1.0 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: "Rafael J. Wysocki" When intel_pstate switches the operation mode from "active" to "passive" or the other way around, freeing its data structures representing CPUs and allocating them again from scratch is not necessary and wasteful. Moreover, if these data structures are preserved, the cached HWP Request MSR value from there may be written to the MSR to start with to reinitialize it and help to restore the EPP value set previously (it is set to 0xFF when CPUs go offline to allow their SMT siblings to use the full range of EPP values and that also happens when the driver gets unregistered). Accordingly, modify the driver to only do a full cleanup on driver object registration errors and when its status is changed to "off" via sysfs and to write the cached HWP Request MSR value back to the MSR on CPU init if the data structure representing the given CPU is still there. Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 51 +++++++++++++--------------------- 1 file changed, 19 insertions(+), 32 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index aca0587b176f..a7c6491f2b4a 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -2091,30 +2091,32 @@ static int intel_pstate_init_cpu(unsigned int cpunum) cpu = all_cpu_data[cpunum]; - if (!cpu) { + if (cpu) { + if (hwp_active) + wrmsrl_on_cpu(cpunum, MSR_HWP_REQUEST, + cpu->hwp_req_cached); + } else { cpu = kzalloc(sizeof(*cpu), GFP_KERNEL); if (!cpu) return -ENOMEM; all_cpu_data[cpunum] = cpu; + cpu->cpu = cpunum; + cpu->epp_default = -EINVAL; cpu->epp_powersave = -EINVAL; cpu->epp_saved = -EINVAL; - } - - cpu = all_cpu_data[cpunum]; - cpu->cpu = cpunum; + if (hwp_active) { + const struct x86_cpu_id *id; - if (hwp_active) { - const struct x86_cpu_id *id; + intel_pstate_hwp_enable(cpu); - intel_pstate_hwp_enable(cpu); - - id = x86_match_cpu(intel_pstate_hwp_boost_ids); - if (id && intel_pstate_acpi_pm_profile_server()) - hwp_boost = true; + id = x86_match_cpu(intel_pstate_hwp_boost_ids); + if (id && intel_pstate_acpi_pm_profile_server()) + hwp_boost = true; + } } intel_pstate_get_cpu_pstates(cpu); @@ -2701,9 +2703,6 @@ static void intel_pstate_driver_cleanup(void) } put_online_cpus(); - if (intel_pstate_driver == &intel_pstate) - intel_pstate_sysfs_hide_hwp_dynamic_boost(); - intel_pstate_driver = NULL; } @@ -2729,14 +2728,6 @@ static int intel_pstate_register_driver(struct cpufreq_driver *driver) return 0; } -static int intel_pstate_unregister_driver(void) -{ - cpufreq_unregister_driver(intel_pstate_driver); - intel_pstate_driver_cleanup(); - - return 0; -} - static ssize_t intel_pstate_show_status(char *buf) { if (!intel_pstate_driver) @@ -2748,8 +2739,6 @@ static ssize_t intel_pstate_show_status(char *buf) static int intel_pstate_update_status(const char *buf, size_t size) { - int ret; - if (size == 3 && !strncmp(buf, "off", size)) { if (!intel_pstate_driver) return -EINVAL; @@ -2757,7 +2746,8 @@ static int intel_pstate_update_status(const char *buf, size_t size) if (hwp_active) return -EBUSY; - return intel_pstate_unregister_driver(); + cpufreq_unregister_driver(intel_pstate_driver); + intel_pstate_driver_cleanup(); } if (size == 6 && !strncmp(buf, "active", size)) { @@ -2765,9 +2755,7 @@ static int intel_pstate_update_status(const char *buf, size_t size) if (intel_pstate_driver == &intel_pstate) return 0; - ret = intel_pstate_unregister_driver(); - if (ret) - return ret; + cpufreq_unregister_driver(intel_pstate_driver); } return intel_pstate_register_driver(&intel_pstate); @@ -2778,9 +2766,8 @@ static int intel_pstate_update_status(const char *buf, size_t size) if (intel_pstate_driver == &intel_cpufreq) return 0; - ret = intel_pstate_unregister_driver(); - if (ret) - return ret; + cpufreq_unregister_driver(intel_pstate_driver); + intel_pstate_sysfs_hide_hwp_dynamic_boost(); } return intel_pstate_register_driver(&intel_cpufreq);