From patchwork Mon Nov 30 18:37:55 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: 11941133 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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 A164FC63777 for ; Mon, 30 Nov 2020 18:39:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 642152074A for ; Mon, 30 Nov 2020 18:39:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388138AbgK3Sjs (ORCPT ); Mon, 30 Nov 2020 13:39:48 -0500 Received: from cloudserver094114.home.pl ([79.96.170.134]:61374 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388112AbgK3Sjs (ORCPT ); Mon, 30 Nov 2020 13:39:48 -0500 Received: from 89-64-87-210.dynamic.chello.pl (89.64.87.210) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.530) id 6703218980216aac; Mon, 30 Nov 2020 19:39:05 +0100 From: "Rafael J. Wysocki" To: Linux PM Cc: LKML , Viresh Kumar , Srinivas Pandruvada , Peter Zijlstra , Doug Smythies , Giovanni Gherdovich Subject: [RFC][PATCH 2/2] cpufreq: intel_pstate: Implement the ->adjust_perf() callback Date: Mon, 30 Nov 2020 19:37:55 +0100 Message-ID: <9641625.O8ij7EI7nc@kreacher> In-Reply-To: <1817571.2o5Kk4Ohv2@kreacher> References: <1817571.2o5Kk4Ohv2@kreacher> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Rafael J. Wysocki Make intel_pstate expose the ->adjust_perf() callback when it operates in the passive mode with HWP enabled which causes the schedutil governor to use that callback instead of ->fast_switch(). The minimum and target performance-level values passed by the governor to ->adjust_perf() are converted to HWP.REQ.MIN and HWP.REQ.DESIRED, respectively, which allows the processor to adjust its configuration to maximize energy-efficiency while providing sufficient capacity. The "busy" argument of ->adjust_perf() is used to omit updates that are likely to cause performance to drop below the expected level. Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 77 ++++++++++++++++++++++++++++++++++------- 1 file changed, 65 insertions(+), 12 deletions(-) Index: linux-pm/drivers/cpufreq/intel_pstate.c =================================================================== --- linux-pm.orig/drivers/cpufreq/intel_pstate.c +++ linux-pm/drivers/cpufreq/intel_pstate.c @@ -2526,20 +2526,19 @@ static void intel_cpufreq_trace(struct c fp_toint(cpu->iowait_boost * 100)); } -static void intel_cpufreq_adjust_hwp(struct cpudata *cpu, u32 target_pstate, - bool strict, bool fast_switch) +static void intel_cpufreq_adjust_hwp(struct cpudata *cpu, u32 min, u32 max, + u32 desired, bool fast_switch) { u64 prev = READ_ONCE(cpu->hwp_req_cached), value = prev; value &= ~HWP_MIN_PERF(~0L); - value |= HWP_MIN_PERF(target_pstate); + value |= HWP_MIN_PERF(min); - /* - * The entire MSR needs to be updated in order to update the HWP min - * field in it, so opportunistically update the max too if needed. - */ value &= ~HWP_MAX_PERF(~0L); - value |= HWP_MAX_PERF(strict ? target_pstate : cpu->max_perf_ratio); + value |= HWP_MAX_PERF(max); + + value &= ~HWP_DESIRED_PERF(~0L); + value |= HWP_DESIRED_PERF(desired); if (value == prev) return; @@ -2569,11 +2568,15 @@ static int intel_cpufreq_update_pstate(s int old_pstate = cpu->pstate.current_pstate; target_pstate = intel_pstate_prepare_request(cpu, target_pstate); - if (hwp_active) - intel_cpufreq_adjust_hwp(cpu, target_pstate, - policy->strict_target, fast_switch); - else if (target_pstate != old_pstate) + if (hwp_active) { + int max_pstate = policy->strict_target ? + target_pstate : cpu->max_perf_ratio; + + intel_cpufreq_adjust_hwp(cpu, target_pstate, max_pstate, 0, + fast_switch); + } else if (target_pstate != old_pstate) { intel_cpufreq_adjust_perf_ctl(cpu, target_pstate, fast_switch); + } cpu->pstate.current_pstate = target_pstate; @@ -2634,6 +2637,54 @@ static unsigned int intel_cpufreq_fast_s return target_pstate * cpu->pstate.scaling; } +static void intel_cpufreq_adjust_perf(unsigned int cpunum, bool busy, + unsigned long min_perf, + unsigned long target_perf, + unsigned long capacity) +{ + struct cpudata *cpu = all_cpu_data[cpunum]; + int old_pstate = cpu->pstate.current_pstate; + int cap_pstate, min_pstate, max_pstate, target_pstate; + + update_turbo_state(); + cap_pstate = global.turbo_disabled ? cpu->pstate.max_pstate : + cpu->pstate.turbo_pstate; + + /* Optimization: Avoid unnecessary divisions. */ + + target_pstate = cap_pstate; + if (target_perf < capacity) { + target_pstate = DIV_ROUND_UP(cap_pstate * target_perf, capacity); + /* + * Do not reduce the target P-state if the CPU has been busy + * recently, as the reduction is likely to be premature then. + */ + if (target_pstate < old_pstate && busy) + target_pstate = old_pstate; + } + + min_pstate = cap_pstate; + if (min_perf < capacity) + min_pstate = DIV_ROUND_UP(cap_pstate * min_perf, capacity); + + if (min_pstate < cpu->pstate.min_pstate) + min_pstate = cpu->pstate.min_pstate; + + if (min_pstate < cpu->min_perf_ratio) + min_pstate = cpu->min_perf_ratio; + + max_pstate = min(cap_pstate, cpu->max_perf_ratio); + if (max_pstate < min_pstate) + max_pstate = min_pstate; + + target_pstate = clamp_t(int, target_pstate, min_pstate, max_pstate); + + intel_cpufreq_adjust_hwp(cpu, min_pstate, max_pstate, target_pstate, true); + + cpu->pstate.current_pstate = target_pstate; + intel_cpufreq_trace(cpu, INTEL_PSTATE_TRACE_FAST_SWITCH, old_pstate); +} + static int intel_cpufreq_cpu_init(struct cpufreq_policy *policy) { int max_state, turbo_max, min_freq, max_freq, ret; @@ -3032,6 +3083,8 @@ static int __init intel_pstate_init(void intel_pstate.attr = hwp_cpufreq_attrs; intel_cpufreq.attr = hwp_cpufreq_attrs; intel_cpufreq.flags |= CPUFREQ_NEED_UPDATE_LIMITS; + intel_cpufreq.fast_switch = NULL; + intel_cpufreq.adjust_perf = intel_cpufreq_adjust_perf; if (!default_driver) default_driver = &intel_pstate;