X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fcpufreq%2Fcpufreq_conservative.c;h=eef0270c6f3ddf98b23b3495628a60894199ec10;hb=refs%2Fheads%2Fvserver;hp=ac38766b2583eec5b5db349b7227e443d6b1177c;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c index ac38766b2..eef0270c6 100644 --- a/drivers/cpufreq/cpufreq_conservative.c +++ b/drivers/cpufreq/cpufreq_conservative.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -35,12 +36,7 @@ */ #define DEF_FREQUENCY_UP_THRESHOLD (80) -#define MIN_FREQUENCY_UP_THRESHOLD (0) -#define MAX_FREQUENCY_UP_THRESHOLD (100) - #define DEF_FREQUENCY_DOWN_THRESHOLD (20) -#define MIN_FREQUENCY_DOWN_THRESHOLD (0) -#define MAX_FREQUENCY_DOWN_THRESHOLD (100) /* * The polling frequency of this governor depends on the capability of @@ -48,31 +44,47 @@ * latency of the processor. The governor will work on any processor with * transition latency <= 10mS, using appropriate sampling * rate. - * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL) - * this governor will not work. + * For CPUs with transition latency > 10mS (mostly drivers + * with CPUFREQ_ETERNAL), this governor will not work. * All times here are in uS. */ static unsigned int def_sampling_rate; -#define MIN_SAMPLING_RATE (def_sampling_rate / 2) +#define MIN_SAMPLING_RATE_RATIO (2) +/* for correct statistics, we need at least 10 ticks between each measure */ +#define MIN_STAT_SAMPLING_RATE \ + (MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10)) +#define MIN_SAMPLING_RATE \ + (def_sampling_rate / MIN_SAMPLING_RATE_RATIO) #define MAX_SAMPLING_RATE (500 * def_sampling_rate) -#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (100000) -#define DEF_SAMPLING_DOWN_FACTOR (5) +#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000) +#define DEF_SAMPLING_DOWN_FACTOR (1) +#define MAX_SAMPLING_DOWN_FACTOR (10) #define TRANSITION_LATENCY_LIMIT (10 * 1000) -static void do_dbs_timer(void *data); +static void do_dbs_timer(struct work_struct *work); struct cpu_dbs_info_s { struct cpufreq_policy *cur_policy; unsigned int prev_cpu_idle_up; unsigned int prev_cpu_idle_down; unsigned int enable; + unsigned int down_skip; + unsigned int requested_freq; }; static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info); static unsigned int dbs_enable; /* number of CPUs using this policy */ +/* + * DEADLOCK ALERT! There is a ordering requirement between cpu_hotplug + * lock and dbs_mutex. cpu_hotplug lock should always be held before + * dbs_mutex. If any function that can potentially take cpu_hotplug lock + * (like __cpufreq_driver_target()) is being called with dbs_mutex taken, then + * cpu_hotplug lock should be taken before that. Note that cpu_hotplug lock + * is recursive for the same process. -Venki + */ static DEFINE_MUTEX (dbs_mutex); -static DECLARE_WORK (dbs_work, do_dbs_timer, NULL); +static DECLARE_DELAYED_WORK(dbs_work, do_dbs_timer); struct dbs_tuners { unsigned int sampling_rate; @@ -87,15 +99,22 @@ static struct dbs_tuners dbs_tuners_ins = { .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, .down_threshold = DEF_FREQUENCY_DOWN_THRESHOLD, .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR, + .ignore_nice = 0, + .freq_step = 5, }; static inline unsigned int get_cpu_idle_time(unsigned int cpu) { - return kstat_cpu(cpu).cpustat.idle + + unsigned int add_nice = 0, ret; + + if (dbs_tuners_ins.ignore_nice) + add_nice = kstat_cpu(cpu).cpustat.nice; + + ret = kstat_cpu(cpu).cpustat.idle + kstat_cpu(cpu).cpustat.iowait + - ( dbs_tuners_ins.ignore_nice ? - kstat_cpu(cpu).cpustat.nice : - 0); + add_nice; + + return ret; } /************************** sysfs interface ************************/ @@ -136,7 +155,7 @@ static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused, unsigned int input; int ret; ret = sscanf (buf, "%u", &input); - if (ret != 1 ) + if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) return -EINVAL; mutex_lock(&dbs_mutex); @@ -173,9 +192,7 @@ static ssize_t store_up_threshold(struct cpufreq_policy *unused, ret = sscanf (buf, "%u", &input); mutex_lock(&dbs_mutex); - if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || - input < MIN_FREQUENCY_UP_THRESHOLD || - input <= dbs_tuners_ins.down_threshold) { + if (ret != 1 || input > 100 || input <= dbs_tuners_ins.down_threshold) { mutex_unlock(&dbs_mutex); return -EINVAL; } @@ -194,9 +211,7 @@ static ssize_t store_down_threshold(struct cpufreq_policy *unused, ret = sscanf (buf, "%u", &input); mutex_lock(&dbs_mutex); - if (ret != 1 || input > MAX_FREQUENCY_DOWN_THRESHOLD || - input < MIN_FREQUENCY_DOWN_THRESHOLD || - input >= dbs_tuners_ins.up_threshold) { + if (ret != 1 || input > 100 || input >= dbs_tuners_ins.up_threshold) { mutex_unlock(&dbs_mutex); return -EINVAL; } @@ -297,31 +312,17 @@ static struct attribute_group dbs_attr_group = { static void dbs_check_cpu(int cpu) { unsigned int idle_ticks, up_idle_ticks, down_idle_ticks; + unsigned int tmp_idle_ticks, total_idle_ticks; unsigned int freq_step; unsigned int freq_down_sampling_rate; - static int down_skip[NR_CPUS]; - static int requested_freq[NR_CPUS]; - static unsigned short init_flag = 0; - struct cpu_dbs_info_s *this_dbs_info; - struct cpu_dbs_info_s *dbs_info; - + struct cpu_dbs_info_s *this_dbs_info = &per_cpu(cpu_dbs_info, cpu); struct cpufreq_policy *policy; - unsigned int j; - this_dbs_info = &per_cpu(cpu_dbs_info, cpu); if (!this_dbs_info->enable) return; policy = this_dbs_info->cur_policy; - if ( init_flag == 0 ) { - for_each_online_cpu(j) { - dbs_info = &per_cpu(cpu_dbs_info, j); - requested_freq[j] = dbs_info->cur_policy->cur; - } - init_flag = 1; - } - /* * The default safe range is 20% to 80% * Every sampling_rate, we check @@ -337,39 +338,29 @@ static void dbs_check_cpu(int cpu) */ /* Check for frequency increase */ - idle_ticks = UINT_MAX; - for_each_cpu_mask(j, policy->cpus) { - unsigned int tmp_idle_ticks, total_idle_ticks; - struct cpu_dbs_info_s *j_dbs_info; - j_dbs_info = &per_cpu(cpu_dbs_info, j); - /* Check for frequency increase */ - total_idle_ticks = get_cpu_idle_time(j); - tmp_idle_ticks = total_idle_ticks - - j_dbs_info->prev_cpu_idle_up; - j_dbs_info->prev_cpu_idle_up = total_idle_ticks; - - if (tmp_idle_ticks < idle_ticks) - idle_ticks = tmp_idle_ticks; - } + /* Check for frequency increase */ + total_idle_ticks = get_cpu_idle_time(cpu); + tmp_idle_ticks = total_idle_ticks - + this_dbs_info->prev_cpu_idle_up; + this_dbs_info->prev_cpu_idle_up = total_idle_ticks; + + if (tmp_idle_ticks < idle_ticks) + idle_ticks = tmp_idle_ticks; /* Scale idle ticks by 100 and compare with up and down ticks */ idle_ticks *= 100; up_idle_ticks = (100 - dbs_tuners_ins.up_threshold) * - usecs_to_jiffies(dbs_tuners_ins.sampling_rate); + usecs_to_jiffies(dbs_tuners_ins.sampling_rate); if (idle_ticks < up_idle_ticks) { - down_skip[cpu] = 0; - for_each_cpu_mask(j, policy->cpus) { - struct cpu_dbs_info_s *j_dbs_info; + this_dbs_info->down_skip = 0; + this_dbs_info->prev_cpu_idle_down = + this_dbs_info->prev_cpu_idle_up; - j_dbs_info = &per_cpu(cpu_dbs_info, j); - j_dbs_info->prev_cpu_idle_down = - j_dbs_info->prev_cpu_idle_up; - } /* if we are already at full speed then break out early */ - if (requested_freq[cpu] == policy->max) + if (this_dbs_info->requested_freq == policy->max) return; freq_step = (dbs_tuners_ins.freq_step * policy->max) / 100; @@ -378,49 +369,45 @@ static void dbs_check_cpu(int cpu) if (unlikely(freq_step == 0)) freq_step = 5; - requested_freq[cpu] += freq_step; - if (requested_freq[cpu] > policy->max) - requested_freq[cpu] = policy->max; + this_dbs_info->requested_freq += freq_step; + if (this_dbs_info->requested_freq > policy->max) + this_dbs_info->requested_freq = policy->max; - __cpufreq_driver_target(policy, requested_freq[cpu], + __cpufreq_driver_target(policy, this_dbs_info->requested_freq, CPUFREQ_RELATION_H); return; } /* Check for frequency decrease */ - down_skip[cpu]++; - if (down_skip[cpu] < dbs_tuners_ins.sampling_down_factor) + this_dbs_info->down_skip++; + if (this_dbs_info->down_skip < dbs_tuners_ins.sampling_down_factor) return; - idle_ticks = UINT_MAX; - for_each_cpu_mask(j, policy->cpus) { - unsigned int tmp_idle_ticks, total_idle_ticks; - struct cpu_dbs_info_s *j_dbs_info; - - j_dbs_info = &per_cpu(cpu_dbs_info, j); - total_idle_ticks = j_dbs_info->prev_cpu_idle_up; - tmp_idle_ticks = total_idle_ticks - - j_dbs_info->prev_cpu_idle_down; - j_dbs_info->prev_cpu_idle_down = total_idle_ticks; + /* Check for frequency decrease */ + total_idle_ticks = this_dbs_info->prev_cpu_idle_up; + tmp_idle_ticks = total_idle_ticks - + this_dbs_info->prev_cpu_idle_down; + this_dbs_info->prev_cpu_idle_down = total_idle_ticks; - if (tmp_idle_ticks < idle_ticks) - idle_ticks = tmp_idle_ticks; - } + if (tmp_idle_ticks < idle_ticks) + idle_ticks = tmp_idle_ticks; /* Scale idle ticks by 100 and compare with up and down ticks */ idle_ticks *= 100; - down_skip[cpu] = 0; + this_dbs_info->down_skip = 0; freq_down_sampling_rate = dbs_tuners_ins.sampling_rate * dbs_tuners_ins.sampling_down_factor; down_idle_ticks = (100 - dbs_tuners_ins.down_threshold) * - usecs_to_jiffies(freq_down_sampling_rate); + usecs_to_jiffies(freq_down_sampling_rate); if (idle_ticks > down_idle_ticks) { - /* if we are already at the lowest speed then break out early + /* + * if we are already at the lowest speed then break out early * or if we 'cannot' reduce the speed as the user might want - * freq_step to be zero */ - if (requested_freq[cpu] == policy->min + * freq_step to be zero + */ + if (this_dbs_info->requested_freq == policy->min || dbs_tuners_ins.freq_step == 0) return; @@ -430,31 +417,31 @@ static void dbs_check_cpu(int cpu) if (unlikely(freq_step == 0)) freq_step = 5; - requested_freq[cpu] -= freq_step; - if (requested_freq[cpu] < policy->min) - requested_freq[cpu] = policy->min; + this_dbs_info->requested_freq -= freq_step; + if (this_dbs_info->requested_freq < policy->min) + this_dbs_info->requested_freq = policy->min; - __cpufreq_driver_target(policy, - requested_freq[cpu], - CPUFREQ_RELATION_H); + __cpufreq_driver_target(policy, this_dbs_info->requested_freq, + CPUFREQ_RELATION_H); return; } } -static void do_dbs_timer(void *data) +static void do_dbs_timer(struct work_struct *work) { int i; + lock_cpu_hotplug(); mutex_lock(&dbs_mutex); for_each_online_cpu(i) dbs_check_cpu(i); schedule_delayed_work(&dbs_work, usecs_to_jiffies(dbs_tuners_ins.sampling_rate)); mutex_unlock(&dbs_mutex); + unlock_cpu_hotplug(); } static inline void dbs_timer_init(void) { - INIT_WORK(&dbs_work, do_dbs_timer, NULL); schedule_delayed_work(&dbs_work, usecs_to_jiffies(dbs_tuners_ins.sampling_rate)); return; @@ -472,6 +459,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, unsigned int cpu = policy->cpu; struct cpu_dbs_info_s *this_dbs_info; unsigned int j; + int rc; this_dbs_info = &per_cpu(cpu_dbs_info, cpu); @@ -488,17 +476,26 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, break; mutex_lock(&dbs_mutex); + + rc = sysfs_create_group(&policy->kobj, &dbs_attr_group); + if (rc) { + mutex_unlock(&dbs_mutex); + return rc; + } + for_each_cpu_mask(j, policy->cpus) { struct cpu_dbs_info_s *j_dbs_info; j_dbs_info = &per_cpu(cpu_dbs_info, j); j_dbs_info->cur_policy = policy; - j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(j); + j_dbs_info->prev_cpu_idle_up = get_cpu_idle_time(cpu); j_dbs_info->prev_cpu_idle_down = j_dbs_info->prev_cpu_idle_up; } this_dbs_info->enable = 1; - sysfs_create_group(&policy->kobj, &dbs_attr_group); + this_dbs_info->down_skip = 0; + this_dbs_info->requested_freq = policy->cur; + dbs_enable++; /* * Start the timerschedule work, when this governor @@ -507,16 +504,17 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, if (dbs_enable == 1) { unsigned int latency; /* policy latency is in nS. Convert it to uS first */ + latency = policy->cpuinfo.transition_latency / 1000; + if (latency == 0) + latency = 1; - latency = policy->cpuinfo.transition_latency; - if (latency < 1000) - latency = 1000; - - def_sampling_rate = (latency / 1000) * + def_sampling_rate = 10 * latency * DEF_SAMPLING_RATE_LATENCY_MULTIPLIER; + + if (def_sampling_rate < MIN_STAT_SAMPLING_RATE) + def_sampling_rate = MIN_STAT_SAMPLING_RATE; + dbs_tuners_ins.sampling_rate = def_sampling_rate; - dbs_tuners_ins.ignore_nice = 0; - dbs_tuners_ins.freq_step = 5; dbs_timer_init(); }