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intel_pstate: Do not set utilization update hook too early

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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 <rafael.j.wysocki@intel.com>
This commit is contained in:
Rafael J. Wysocki 2016-03-31 17:42:15 +02:00
parent 539a4c4247
commit bb6ab52f2b
1 changed files with 19 additions and 8 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

27
drivers/cpufreq/intel_pstate.c
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@ -1103,7 +1103,6 @@ static int intel_pstate_init_cpu(unsigned int cpunum)
intel_pstate_sample(cpu, 0); intel_pstate_sample(cpu, 0);
cpu->update_util.func = intel_pstate_update_util; 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); 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); 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) static int intel_pstate_set_policy(struct cpufreq_policy *policy)
{ {
if (!policy->cpuinfo.max_freq) if (!policy->cpuinfo.max_freq)
return -ENODEV; return -ENODEV;
intel_pstate_clear_update_util_hook(policy->cpu);
if (policy->policy == CPUFREQ_POLICY_PERFORMANCE && if (policy->policy == CPUFREQ_POLICY_PERFORMANCE &&
policy->max >= policy->cpuinfo.max_freq) { policy->max >= policy->cpuinfo.max_freq) {
pr_debug("intel_pstate: set performance\n"); pr_debug("intel_pstate: set performance\n");
limits = &performance_limits; limits = &performance_limits;
if (hwp_active) goto out;
intel_pstate_hwp_set(policy->cpus);
return 0;
} }
pr_debug("intel_pstate: set powersave\n"); 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), limits->max_perf = div_fp(int_tofp(limits->max_perf_pct),
int_tofp(100)); int_tofp(100));
out:
intel_pstate_set_update_util_hook(policy->cpu);
if (hwp_active) if (hwp_active)
intel_pstate_hwp_set(policy->cpus); 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); pr_debug("intel_pstate: CPU %d exiting\n", cpu_num);
cpufreq_set_update_util_data(cpu_num, NULL); intel_pstate_clear_update_util_hook(cpu_num);
synchronize_sched();
if (hwp_active) if (hwp_active)
return; return;
@ -1455,8 +1467,7 @@ static int __init intel_pstate_init(void)
get_online_cpus(); get_online_cpus();
for_each_online_cpu(cpu) { for_each_online_cpu(cpu) {
if (all_cpu_data[cpu]) { if (all_cpu_data[cpu]) {
cpufreq_set_update_util_data(cpu, NULL); intel_pstate_clear_update_util_hook(cpu);
synchronize_sched();
kfree(all_cpu_data[cpu]); kfree(all_cpu_data[cpu]);
} }
} }