static unsigned long determine_cpu_load_trend(void)
{
int i, k;
unsigned long total_load = 0;
/* Get cpu load of each cpu */
for_each_online_cpu(i) {
unsigned int load = 0;
struct hotplug_cpu_info *info;
info = &per_cpu(hotplug_info, i);
for (k = 0; k < LOAD_MONITOR; k++)
load += info->load[k];
load /= LOAD_MONITOR;
#ifdef CONFIG_DEBUG_PRINTK
hp_printk("cpu %d load trend %u\n", i, load);
#else
hp_;
#endif
total_load += load;
}
return total_load;
}
static unsigned long determine_cpu_load(void)
{
int i;
unsigned long total_load = 0;
/* get cpu load of each cpu */
for_each_online_cpu(i) {
unsigned int load;
unsigned int idle_time, wall_time;
cputime64_t cur_wall_time, cur_idle_time;
struct hotplug_cpu_info *info;
info = &per_cpu(hotplug_info, i);
/* update both cur_idle_time and cur_wall_time */
cur_idle_time = get_cpu_idle_time_us(i, &cur_wall_time);
/* how much wall time has passed since last iteration? */
wall_time = (unsigned int) cputime64_sub(cur_wall_time,
info->prev_cpu_wall);
info->prev_cpu_wall = cur_wall_time;
/* how much idle time has passed since last iteration? */
idle_time = (unsigned int) cputime64_sub(cur_idle_time,
info->prev_cpu_idle);
info->prev_cpu_idle = cur_idle_time;
if (unlikely(!wall_time || wall_time < idle_time))
continue;
/* load is the percentage of time not spent in idle */
load = 100 * (wall_time - idle_time) / wall_time;
info->load[info->idx++] = load;
if (info->idx >= LOAD_MONITOR)
info->idx = 0;
#ifdef CONFIG_DEBUG_PRINTK
hp_printk("cpu %d load %u ", i, load);
#else
hp_;
#endif
total_load += load;
}
return total_load / num_online_cpus();
}
static void delayed_usecase_work(struct work_struct *work)
{
unsigned long avg, load, trend, balance;
bool inc_perf = false;
bool dec_perf = false;
u32 irqs_per_s;
/* determine loadavg */
avg = determine_loadavg();
hp_printk("loadavg = %lu lower th %lu upper th %lu\n",
avg, lower_threshold, upper_threshold);
/* determine instant load */
load = determine_cpu_load();
hp_printk("cpu instant load = %lu max %lu\n", load, max_instant);
/* determine load trend */
trend = determine_cpu_load_trend();
hp_printk("cpu load trend = %lu min %lu unbal %lu\n",
trend, min_trend, trend_unbalance);
/* determine load balancing */
balance = determine_cpu_balance_trend();
hp_printk("load balancing trend = %lu min %lu\n",
balance, max_unbalance);
irqs_per_s = get_num_interrupts_per_s();
/* Dont let configuration change in the middle of our calculations. */
mutex_lock(&usecase_mutex);
/* detect "instant" load increase */
if (load > max_instant || irqs_per_s > exit_irq_per_s) {
inc_perf = true;
} else if (!usecase_conf[UX500_UC_USER].enable &&
usecase_conf[UX500_UC_AUTO].enable) {
/* detect high loadavg use case */
if (avg > upper_threshold)
inc_perf = true;
/* detect idle use case */
else if (trend < min_trend)
dec_perf = true;
/* detect unbalanced low cpu load use case */
else if ((balance > max_unbalance) && (trend < trend_unbalance))
dec_perf = true;
/* detect low loadavg use case */
else if (avg < lower_threshold)
dec_perf = true;
/* All user use cases disabled, current load not triggering
* any change.
*/
else if (user_config_updated)
dec_perf = true;
} else {
dec_perf = true;
}
/*
* set_cpu_config() will not update the config unless it has been
* changed.
*/
if (dec_perf) {
if (usecase_conf[UX500_UC_USER].enable)
set_cpu_config(UX500_UC_USER);
else if (usecase_conf[UX500_UC_AUTO].enable)
set_cpu_config(UX500_UC_AUTO);
} else if (inc_perf &&
!(usecase_conf[UX500_UC_USER].enable &&
usecase_conf[UX500_UC_USER].force_usecase)) {
set_cpu_config(UX500_UC_NORMAL);
}
mutex_unlock(&usecase_mutex);
/* reprogramm scheduled work */
schedule_delayed_work_on(0, &work_usecase,
msecs_to_jiffies(CPULOAD_MEAS_DELAY));
}
