From 7e3e9112a1583fa71f1a775490cb8144c476f32c Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Mon, 29 Jul 2019 13:43:01 +0800 Subject: [PATCH] cpufreq: intel_pstate: Force HWP min perf before offline commit af3b7379e2d709f2d7c6966b8a6f5ec6bd134241 upstream. Force HWP Request MAX = HWP Request MIN = HWP Capability MIN and EPP to 0xFF. In this way the performance limits on the offlined CPU will not influence performance limits on its sibling CPU, which is still online. If the sibling CPU is calling for higher performance, it will impact the max core performance. Here core performance will follow higher of the performance requests from each sibling. Reported-and-tested-by: Chen Yu Signed-off-by: Srinivas Pandruvada Signed-off-by: Rafael J. Wysocki Signed-off-by: Shanpei Chen Acked-by: Michael Wang --- drivers/cpufreq/intel_pstate.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 29f25d5d65e0..b4341b51d223 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -790,6 +790,28 @@ static void intel_pstate_hwp_set(unsigned int cpu) wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value); } +static void intel_pstate_hwp_force_min_perf(int cpu) +{ + u64 value; + int min_perf; + + value = all_cpu_data[cpu]->hwp_req_cached; + value &= ~GENMASK_ULL(31, 0); + min_perf = HWP_LOWEST_PERF(all_cpu_data[cpu]->hwp_cap_cached); + + /* Set hwp_max = hwp_min */ + value |= HWP_MAX_PERF(min_perf); + value |= HWP_MIN_PERF(min_perf); + + /* Set EPP/EPB to min */ + if (static_cpu_has(X86_FEATURE_HWP_EPP)) + value |= HWP_ENERGY_PERF_PREFERENCE(HWP_EPP_POWERSAVE); + else + intel_pstate_set_epb(cpu, HWP_EPP_BALANCE_POWERSAVE); + + wrmsrl_on_cpu(cpu, MSR_HWP_REQUEST, value); +} + static int intel_pstate_hwp_save_state(struct cpufreq_policy *policy) { struct cpudata *cpu_data = all_cpu_data[policy->cpu]; @@ -2045,10 +2067,12 @@ static void intel_pstate_stop_cpu(struct cpufreq_policy *policy) pr_debug("CPU %d exiting\n", policy->cpu); intel_pstate_clear_update_util_hook(policy->cpu); - if (hwp_active) + if (hwp_active) { intel_pstate_hwp_save_state(policy); - else + intel_pstate_hwp_force_min_perf(policy->cpu); + } else { intel_cpufreq_stop_cpu(policy); + } } static int intel_pstate_cpu_exit(struct cpufreq_policy *policy) -- GitLab