Merge back intel_pstate fixes for v4.6.
* pm-cpufreq:
intel_pstate: Avoid extra invocation of intel_pstate_sample()
intel_pstate: Do not set utilization update hook too early
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index 4b64452..9ae1596 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -910,7 +910,14 @@
cpu->prev_aperf = aperf;
cpu->prev_mperf = mperf;
cpu->prev_tsc = tsc;
- return true;
+ /*
+ * First time this function is invoked in a given cycle, all of the
+ * previous sample data fields are equal to zero or stale and they must
+ * be populated with meaningful numbers for things to work, so assume
+ * that sample.time will always be reset before setting the utilization
+ * update hook and make the caller skip the sample then.
+ */
+ return !!cpu->last_sample_time;
}
static inline int32_t get_avg_frequency(struct cpudata *cpu)
@@ -984,8 +991,7 @@
* enough period of time to adjust our busyness.
*/
duration_ns = cpu->sample.time - cpu->last_sample_time;
- if ((s64)duration_ns > pid_params.sample_rate_ns * 3
- && cpu->last_sample_time > 0) {
+ if ((s64)duration_ns > pid_params.sample_rate_ns * 3) {
sample_ratio = div_fp(int_tofp(pid_params.sample_rate_ns),
int_tofp(duration_ns));
core_busy = mul_fp(core_busy, sample_ratio);
@@ -1100,10 +1106,8 @@
intel_pstate_get_cpu_pstates(cpu);
intel_pstate_busy_pid_reset(cpu);
- 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 +1126,33 @@
return get_avg_frequency(cpu);
}
+static void intel_pstate_set_update_util_hook(unsigned int cpu_num)
+{
+ struct cpudata *cpu = all_cpu_data[cpu_num];
+
+ /* Prevent intel_pstate_update_util() from using stale data. */
+ cpu->sample.time = 0;
+ cpufreq_set_update_util_data(cpu_num, &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 +1182,9 @@
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 +1209,7 @@
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 +1476,7 @@
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]);
}
}