diff options
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 44 |
1 files changed, 32 insertions, 12 deletions
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 @@ static inline bool intel_pstate_sample(struct cpudata *cpu, u64 time) 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 @@ static inline int32_t get_target_pstate_use_performance(struct cpudata *cpu) * 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 @@ static int intel_pstate_init_cpu(unsigned int cpunum) 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 @@ 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_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 @@ 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 +1209,7 @@ 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 +1476,7 @@ 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]); } } |
