From bb6ab52f2befe1fb29ac198f27d8a6aadf510f81 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 31 Mar 2016 17:42:15 +0200 Subject: [PATCH] intel_pstate: Do not set utilization update hook too early The utilization update hook in the intel_pstate driver is set too early, as it only should be set after the policy has been fully initialized by the core. That may cause intel_pstate_update_util() to use incorrect data and put the CPUs into incorrect P-states as a result. To prevent that from happening, make intel_pstate_set_policy() set the utilization update hook instead of intel_pstate_init_cpu() so intel_pstate_update_util() only runs when all things have been initialized as appropriate. Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 4b64452..81057e4 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1103,7 +1103,6 @@ static int intel_pstate_init_cpu(unsigned int cpunum) intel_pstate_sample(cpu, 0); cpu->update_util.func = intel_pstate_update_util; - cpufreq_set_update_util_data(cpunum, &cpu->update_util); pr_debug("intel_pstate: controlling: cpu %d\n", cpunum); @@ -1122,18 +1121,29 @@ static unsigned int intel_pstate_get(unsigned int cpu_num) return get_avg_frequency(cpu); } +static void intel_pstate_set_update_util_hook(unsigned int cpu) +{ + cpufreq_set_update_util_data(cpu, &all_cpu_data[cpu]->update_util); +} + +static void intel_pstate_clear_update_util_hook(unsigned int cpu) +{ + cpufreq_set_update_util_data(cpu, NULL); + synchronize_sched(); +} + static int intel_pstate_set_policy(struct cpufreq_policy *policy) { if (!policy->cpuinfo.max_freq) return -ENODEV; + intel_pstate_clear_update_util_hook(policy->cpu); + if (policy->policy == CPUFREQ_POLICY_PERFORMANCE && policy->max >= policy->cpuinfo.max_freq) { pr_debug("intel_pstate: set performance\n"); limits = &performance_limits; - if (hwp_active) - intel_pstate_hwp_set(policy->cpus); - return 0; + goto out; } pr_debug("intel_pstate: set powersave\n"); @@ -1163,6 +1173,9 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy) limits->max_perf = div_fp(int_tofp(limits->max_perf_pct), int_tofp(100)); + out: + intel_pstate_set_update_util_hook(policy->cpu); + if (hwp_active) intel_pstate_hwp_set(policy->cpus); @@ -1187,8 +1200,7 @@ static void intel_pstate_stop_cpu(struct cpufreq_policy *policy) pr_debug("intel_pstate: CPU %d exiting\n", cpu_num); - cpufreq_set_update_util_data(cpu_num, NULL); - synchronize_sched(); + intel_pstate_clear_update_util_hook(cpu_num); if (hwp_active) return; @@ -1455,8 +1467,7 @@ out: get_online_cpus(); for_each_online_cpu(cpu) { if (all_cpu_data[cpu]) { - cpufreq_set_update_util_data(cpu, NULL); - synchronize_sched(); + intel_pstate_clear_update_util_hook(cpu); kfree(all_cpu_data[cpu]); } } -- 2.7.4