diff options
Diffstat (limited to 'drivers/cpufreq/cpufreq_ondemand.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq_ondemand.c | 74 |
1 files changed, 48 insertions, 26 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index 6f45b1658a67..338f428a15b7 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -21,6 +21,7 @@ #include <linux/hrtimer.h> #include <linux/tick.h> #include <linux/ktime.h> +#include <linux/sched.h> /* * dbs is used in this file as a shortform for demandbased switching @@ -51,8 +52,20 @@ static unsigned int def_sampling_rate; (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10)) #define MIN_SAMPLING_RATE \ (def_sampling_rate / MIN_SAMPLING_RATE_RATIO) +/* Above MIN_SAMPLING_RATE will vanish with its sysfs file soon + * Define the minimal settable sampling rate to the greater of: + * - "HW transition latency" * 100 (same as default sampling / 10) + * - MIN_STAT_SAMPLING_RATE + * To avoid that userspace shoots itself. +*/ +static unsigned int minimum_sampling_rate(void) +{ + return max(def_sampling_rate / 10, MIN_STAT_SAMPLING_RATE); +} + +/* This will also vanish soon with removing sampling_rate_max */ #define MAX_SAMPLING_RATE (500 * def_sampling_rate) -#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000) +#define LATENCY_MULTIPLIER (1000) #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) static void do_dbs_timer(struct work_struct *work); @@ -65,14 +78,14 @@ struct cpu_dbs_info_s { cputime64_t prev_cpu_wall; cputime64_t prev_cpu_nice; struct cpufreq_policy *cur_policy; - struct delayed_work work; + struct delayed_work work; struct cpufreq_frequency_table *freq_table; unsigned int freq_lo; unsigned int freq_lo_jiffies; unsigned int freq_hi_jiffies; int cpu; unsigned int enable:1, - sample_type:1; + sample_type:1; }; static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info); @@ -203,12 +216,28 @@ static void ondemand_powersave_bias_init(void) /************************** sysfs interface ************************/ static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf) { - return sprintf (buf, "%u\n", MAX_SAMPLING_RATE); + static int print_once; + + if (!print_once) { + printk(KERN_INFO "CPUFREQ: ondemand sampling_rate_max " + "sysfs file is deprecated - used by: %s\n", + current->comm); + print_once = 1; + } + return sprintf(buf, "%u\n", MAX_SAMPLING_RATE); } static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf) { - return sprintf (buf, "%u\n", MIN_SAMPLING_RATE); + static int print_once; + + if (!print_once) { + printk(KERN_INFO "CPUFREQ: ondemand sampling_rate_min " + "sysfs file is deprecated - used by: %s\n", + current->comm); + print_once = 1; + } + return sprintf(buf, "%u\n", MIN_SAMPLING_RATE); } #define define_one_ro(_name) \ @@ -238,13 +267,11 @@ static ssize_t store_sampling_rate(struct cpufreq_policy *unused, ret = sscanf(buf, "%u", &input); mutex_lock(&dbs_mutex); - if (ret != 1 || input > MAX_SAMPLING_RATE - || input < MIN_SAMPLING_RATE) { + if (ret != 1) { mutex_unlock(&dbs_mutex); return -EINVAL; } - - dbs_tuners_ins.sampling_rate = input; + dbs_tuners_ins.sampling_rate = max(input, minimum_sampling_rate()); mutex_unlock(&dbs_mutex); return count; @@ -279,14 +306,14 @@ static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy, unsigned int j; ret = sscanf(buf, "%u", &input); - if ( ret != 1 ) + if (ret != 1) return -EINVAL; - if ( input > 1 ) + if (input > 1) input = 1; mutex_lock(&dbs_mutex); - if ( input == dbs_tuners_ins.ignore_nice ) { /* nothing to do */ + if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */ mutex_unlock(&dbs_mutex); return count; } @@ -337,7 +364,7 @@ define_one_rw(up_threshold); define_one_rw(ignore_nice_load); define_one_rw(powersave_bias); -static struct attribute * dbs_attributes[] = { +static struct attribute *dbs_attributes[] = { &sampling_rate_max.attr, &sampling_rate_min.attr, &sampling_rate.attr, @@ -512,8 +539,7 @@ static void do_dbs_timer(struct work_struct *work) } } else { __cpufreq_driver_target(dbs_info->cur_policy, - dbs_info->freq_lo, - CPUFREQ_RELATION_H); + dbs_info->freq_lo, CPUFREQ_RELATION_H); } queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay); unlock_policy_rwsem_write(cpu); @@ -530,7 +556,7 @@ static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) dbs_info->sample_type = DBS_NORMAL_SAMPLE; INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer); queue_delayed_work_on(dbs_info->cpu, kondemand_wq, &dbs_info->work, - delay); + delay); } static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) @@ -591,11 +617,9 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, if (latency == 0) latency = 1; - def_sampling_rate = latency * - DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; - - if (def_sampling_rate < MIN_STAT_SAMPLING_RATE) - def_sampling_rate = MIN_STAT_SAMPLING_RATE; + def_sampling_rate = + max(latency * LATENCY_MULTIPLIER, + MIN_STAT_SAMPLING_RATE); dbs_tuners_ins.sampling_rate = def_sampling_rate; } @@ -617,12 +641,10 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, mutex_lock(&dbs_mutex); if (policy->max < this_dbs_info->cur_policy->cur) __cpufreq_driver_target(this_dbs_info->cur_policy, - policy->max, - CPUFREQ_RELATION_H); + policy->max, CPUFREQ_RELATION_H); else if (policy->min > this_dbs_info->cur_policy->cur) __cpufreq_driver_target(this_dbs_info->cur_policy, - policy->min, - CPUFREQ_RELATION_L); + policy->min, CPUFREQ_RELATION_L); mutex_unlock(&dbs_mutex); break; } @@ -677,7 +699,7 @@ static void __exit cpufreq_gov_dbs_exit(void) MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>"); MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>"); MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for " - "Low Latency Frequency Transition capable processors"); + "Low Latency Frequency Transition capable processors"); MODULE_LICENSE("GPL"); #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND |