From cef9615a853ebc4972084f7e70b52892557420ac Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Wed, 22 Apr 2009 13:48:29 +0200 Subject: [CPUFREQ] ondemand: Uncouple minimal sampling rate from HZ in NO_HZ case With this patch you have following minimal sampling rate restrictions: Kernel restrictions: If CONFIG_NO_HZ is set, the limit is 10ms fixed. If CONFIG_NO_HZ is not set or no_hz=off boot parameter is used, the limits depend on the CONFIG_HZ option: HZ=1000: min=20000us (20ms) HZ=250: min=80000us (80ms) HZ=100: min=200000us (200ms) HW restrictions: Do not sample/poll more often than HW latency * 100 exported by the low level cpufreq HW driver The higher value of above restrictions is the minimal sampling rate that can be set (and can be seen via ondemand/sampling_rate_min sysfs file) Default sampling rate still is HW latency * 1000, but this will now end up in lower values on latest (Intel and AMD) hardware as these can switch really fast and sampling rate mostly was limited to the 80ms or 200ms (depending on whether HZ=250 or HZ=1000 is used). Signed-off-by: Thomas Renninger Cc: Pallipadi Venkatesh Signed-off-by: Dave Jones --- drivers/cpufreq/cpufreq_ondemand.c | 50 ++++++++++++++++++-------------------- 1 file changed, 23 insertions(+), 27 deletions(-) (limited to 'drivers/cpufreq/cpufreq_ondemand.c') diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index e741c339df7..a235114c3d8 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -32,6 +32,7 @@ #define DEF_FREQUENCY_UP_THRESHOLD (80) #define MICRO_FREQUENCY_DOWN_DIFFERENTIAL (3) #define MICRO_FREQUENCY_UP_THRESHOLD (95) +#define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000) #define MIN_FREQUENCY_UP_THRESHOLD (11) #define MAX_FREQUENCY_UP_THRESHOLD (100) @@ -45,27 +46,12 @@ * this governor will not work. * All times here are in uS. */ -static unsigned int def_sampling_rate; #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) -/* 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) +static unsigned int min_sampling_rate; + #define LATENCY_MULTIPLIER (1000) +#define MIN_LATENCY_MULTIPLIER (100) #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) static void do_dbs_timer(struct work_struct *work); @@ -227,7 +213,7 @@ static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf) current->comm); print_once = 1; } - return sprintf(buf, "%u\n", MAX_SAMPLING_RATE); + return sprintf(buf, "%u\n", -1U); } static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf) @@ -240,7 +226,7 @@ static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf) current->comm); print_once = 1; } - return sprintf(buf, "%u\n", MIN_SAMPLING_RATE); + return sprintf(buf, "%u\n", min_sampling_rate); } #define define_one_ro(_name) \ @@ -274,7 +260,7 @@ static ssize_t store_sampling_rate(struct cpufreq_policy *unused, mutex_unlock(&dbs_mutex); return -EINVAL; } - dbs_tuners_ins.sampling_rate = max(input, minimum_sampling_rate()); + dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate); mutex_unlock(&dbs_mutex); return count; @@ -619,12 +605,12 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, latency = policy->cpuinfo.transition_latency / 1000; if (latency == 0) latency = 1; - - def_sampling_rate = - max(latency * LATENCY_MULTIPLIER, - MIN_STAT_SAMPLING_RATE); - - dbs_tuners_ins.sampling_rate = def_sampling_rate; + /* Bring kernel and HW constraints together */ + min_sampling_rate = max(min_sampling_rate, + MIN_LATENCY_MULTIPLIER * latency); + dbs_tuners_ins.sampling_rate = + max(min_sampling_rate, + latency * LATENCY_MULTIPLIER); } dbs_timer_init(this_dbs_info); @@ -678,6 +664,16 @@ static int __init cpufreq_gov_dbs_init(void) dbs_tuners_ins.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD; dbs_tuners_ins.down_differential = MICRO_FREQUENCY_DOWN_DIFFERENTIAL; + /* + * In no_hz/micro accounting case we set the minimum frequency + * not depending on HZ, but fixed (very low). The deferred + * timer might skip some samples if idle/sleeping as needed. + */ + min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE; + } else { + /* For correct statistics, we need 10 ticks for each measure */ + min_sampling_rate = + MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10); } kondemand_wq = create_workqueue("kondemand"); -- cgit v1.2.3-70-g09d2 From 4f4d1ad6ee69027f51f9d137f7e7d3c863cbc53d Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Wed, 22 Apr 2009 13:48:31 +0200 Subject: [CPUFREQ] Only set sampling_rate_max deprecated, sampling_rate_min is useful Update the documentation accordingly. Cleanup and use printk_once. Signed-off-by: Thomas Renninger Signed-off-by: Dave Jones --- Documentation/cpu-freq/governors.txt | 26 ++++++++++++++------------ drivers/cpufreq/cpufreq_conservative.c | 17 ++--------------- drivers/cpufreq/cpufreq_ondemand.c | 18 ++---------------- 3 files changed, 18 insertions(+), 43 deletions(-) (limited to 'drivers/cpufreq/cpufreq_ondemand.c') diff --git a/Documentation/cpu-freq/governors.txt b/Documentation/cpu-freq/governors.txt index ce73f3eb5dd..aed082f49d0 100644 --- a/Documentation/cpu-freq/governors.txt +++ b/Documentation/cpu-freq/governors.txt @@ -119,10 +119,6 @@ want the kernel to look at the CPU usage and to make decisions on what to do about the frequency. Typically this is set to values of around '10000' or more. It's default value is (cmp. with users-guide.txt): transition_latency * 1000 -The lowest value you can set is: -transition_latency * 100 or it may get restricted to a value where it -makes not sense for the kernel anymore to poll that often which depends -on your HZ config variable (HZ=1000: max=20000us, HZ=250: max=5000). Be aware that transition latency is in ns and sampling_rate is in us, so you get the same sysfs value by default. Sampling rate should always get adjusted considering the transition latency @@ -131,14 +127,20 @@ in the bash (as said, 1000 is default), do: echo `$(($(cat cpuinfo_transition_latency) * 750 / 1000)) \ >ondemand/sampling_rate -show_sampling_rate_(min|max): THIS INTERFACE IS DEPRECATED, DON'T USE IT. -You can use wider ranges now and the general -cpuinfo_transition_latency variable (cmp. with user-guide.txt) can be -used to obtain exactly the same info: -show_sampling_rate_min = transtition_latency * 500 / 1000 -show_sampling_rate_max = transtition_latency * 500000 / 1000 -(divided by 1000 is to illustrate that sampling rate is in us and -transition latency is exported ns). +show_sampling_rate_min: +The sampling rate is limited by the HW transition latency: +transition_latency * 100 +Or by kernel restrictions: +If CONFIG_NO_HZ is set, the limit is 10ms fixed. +If CONFIG_NO_HZ is not set or no_hz=off boot parameter is used, the +limits depend on the CONFIG_HZ option: +HZ=1000: min=20000us (20ms) +HZ=250: min=80000us (80ms) +HZ=100: min=200000us (200ms) +The highest value of kernel and HW latency restrictions is shown and +used as the minimum sampling rate. + +show_sampling_rate_max: THIS INTERFACE IS DEPRECATED, DON'T USE IT. up_threshold: defines what the average CPU usage between the samplings of 'sampling_rate' needs to be for the kernel to make a decision on diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c index 06bfe1c572c..7fc58af748b 100644 --- a/drivers/cpufreq/cpufreq_conservative.c +++ b/drivers/cpufreq/cpufreq_conservative.c @@ -167,26 +167,13 @@ static struct notifier_block dbs_cpufreq_notifier_block = { /************************** sysfs interface ************************/ static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf) { - static int print_once; - - if (!print_once) { - printk(KERN_INFO "CPUFREQ: conservative sampling_rate_max " - "sysfs file is deprecated - used by: %s\n", - current->comm); - print_once = 1; - } + printk_once(KERN_INFO "CPUFREQ: conservative sampling_rate_max " + "sysfs file is deprecated - used by: %s\n", current->comm); return sprintf(buf, "%u\n", -1U); } static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf) { - static int print_once; - - if (!print_once) { - printk(KERN_INFO "CPUFREQ: conservative sampling_rate_max " - "sysfs file is deprecated - used by: %s\n", current->comm); - print_once = 1; - } return sprintf(buf, "%u\n", min_sampling_rate); } diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index a235114c3d8..1911d172935 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -205,27 +205,13 @@ static void ondemand_powersave_bias_init(void) /************************** sysfs interface ************************/ static ssize_t show_sampling_rate_max(struct cpufreq_policy *policy, char *buf) { - 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; - } + printk_once(KERN_INFO "CPUFREQ: ondemand sampling_rate_max " + "sysfs file is deprecated - used by: %s\n", current->comm); return sprintf(buf, "%u\n", -1U); } static ssize_t show_sampling_rate_min(struct cpufreq_policy *policy, char *buf) { - 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); } -- cgit v1.2.3-70-g09d2 From 7d26e2d5e2da37e92c6c7644b26b294dedd8c982 Mon Sep 17 00:00:00 2001 From: "venkatesh.pallipadi@intel.com" Date: Thu, 2 Jul 2009 17:08:30 -0700 Subject: [CPUFREQ] Eliminate the recent lockdep warnings in cpufreq Commit b14893a62c73af0eca414cfed505b8c09efc613c although it was very much needed to properly cleanup ondemand timer, opened-up a can of worms related to locking dependencies in cpufreq. Patch here defines the need for dbs_mutex and cleans up its usage in ondemand governor. This also resolves the lockdep warnings reported here http://lkml.indiana.edu/hypermail/linux/kernel/0906.1/01925.html http://lkml.indiana.edu/hypermail/linux/kernel/0907.0/00820.html and few others.. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Dave Jones --- drivers/cpufreq/cpufreq.c | 4 ++-- drivers/cpufreq/cpufreq_conservative.c | 27 +++++++++++---------------- drivers/cpufreq/cpufreq_ondemand.c | 27 +++++++++++---------------- 3 files changed, 24 insertions(+), 34 deletions(-) (limited to 'drivers/cpufreq/cpufreq_ondemand.c') diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 6e2ec0b1894..c7fe16e0474 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1070,8 +1070,6 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev) spin_unlock_irqrestore(&cpufreq_driver_lock, flags); #endif - unlock_policy_rwsem_write(cpu); - if (cpufreq_driver->target) __cpufreq_governor(data, CPUFREQ_GOV_STOP); @@ -1088,6 +1086,8 @@ static int __cpufreq_remove_dev(struct sys_device *sys_dev) if (cpufreq_driver->exit) cpufreq_driver->exit(data); + unlock_policy_rwsem_write(cpu); + free_cpumask_var(data->related_cpus); free_cpumask_var(data->cpus); kfree(data); diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c index 7fc58af748b..58889f26029 100644 --- a/drivers/cpufreq/cpufreq_conservative.c +++ b/drivers/cpufreq/cpufreq_conservative.c @@ -70,15 +70,10 @@ 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 - * DEADLOCK ALERT! (2) : do_dbs_timer() must not take the dbs_mutex, because it - * would deadlock with cancel_delayed_work_sync(), which is needed for proper - * raceless workqueue teardown. + * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on + * different CPUs. It protects dbs_enable in governor start/stop. It also + * serializes governor limit_change with do_dbs_timer. We do not want + * do_dbs_timer to run when user is changing the governor or limits. */ static DEFINE_MUTEX(dbs_mutex); @@ -488,18 +483,17 @@ static void do_dbs_timer(struct work_struct *work) delay -= jiffies % delay; - if (lock_policy_rwsem_write(cpu) < 0) - return; + mutex_lock(&dbs_mutex); if (!dbs_info->enable) { - unlock_policy_rwsem_write(cpu); + mutex_unlock(&dbs_mutex); return; } dbs_check_cpu(dbs_info); queue_delayed_work_on(cpu, kconservative_wq, &dbs_info->work, delay); - unlock_policy_rwsem_write(cpu); + mutex_unlock(&dbs_mutex); } static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) @@ -590,15 +584,16 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, &dbs_cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER); } - dbs_timer_init(this_dbs_info); - mutex_unlock(&dbs_mutex); + dbs_timer_init(this_dbs_info); + break; case CPUFREQ_GOV_STOP: - mutex_lock(&dbs_mutex); dbs_timer_exit(this_dbs_info); + + mutex_lock(&dbs_mutex); sysfs_remove_group(&policy->kobj, &dbs_attr_group); dbs_enable--; diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index 1911d172935..246ae147df7 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -78,15 +78,10 @@ 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 - * DEADLOCK ALERT! (2) : do_dbs_timer() must not take the dbs_mutex, because it - * would deadlock with cancel_delayed_work_sync(), which is needed for proper - * raceless workqueue teardown. + * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on + * different CPUs. It protects dbs_enable in governor start/stop. It also + * serializes governor limit_change with do_dbs_timer. We do not want + * do_dbs_timer to run when user is changing the governor or limits. */ static DEFINE_MUTEX(dbs_mutex); @@ -494,11 +489,10 @@ static void do_dbs_timer(struct work_struct *work) delay -= jiffies % delay; - if (lock_policy_rwsem_write(cpu) < 0) - return; + mutex_lock(&dbs_mutex); if (!dbs_info->enable) { - unlock_policy_rwsem_write(cpu); + mutex_unlock(&dbs_mutex); return; } @@ -517,7 +511,7 @@ static void do_dbs_timer(struct work_struct *work) dbs_info->freq_lo, CPUFREQ_RELATION_H); } queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay); - unlock_policy_rwsem_write(cpu); + mutex_unlock(&dbs_mutex); } static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) @@ -598,14 +592,15 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, max(min_sampling_rate, latency * LATENCY_MULTIPLIER); } - dbs_timer_init(this_dbs_info); - mutex_unlock(&dbs_mutex); + + dbs_timer_init(this_dbs_info); break; case CPUFREQ_GOV_STOP: - mutex_lock(&dbs_mutex); dbs_timer_exit(this_dbs_info); + + mutex_lock(&dbs_mutex); sysfs_remove_group(&policy->kobj, &dbs_attr_group); dbs_enable--; mutex_unlock(&dbs_mutex); -- cgit v1.2.3-70-g09d2 From 5a75c82828e7c088ca6e7b4827911dc29cc8e774 Mon Sep 17 00:00:00 2001 From: "venkatesh.pallipadi@intel.com" Date: Thu, 2 Jul 2009 17:08:32 -0700 Subject: [CPUFREQ] Cleanup locking in ondemand governor Redesign the locking inside ondemand driver. Make dbs_mutex handle all the global state changes inside the driver and invent a new percpu mutex to serialize percpu timer and frequency limit change. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Dave Jones --- drivers/cpufreq/cpufreq_ondemand.c | 62 +++++++++++++++++--------------------- 1 file changed, 27 insertions(+), 35 deletions(-) (limited to 'drivers/cpufreq/cpufreq_ondemand.c') diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index 246ae147df7..d6ba14276bb 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -70,8 +70,13 @@ struct cpu_dbs_info_s { unsigned int freq_lo_jiffies; unsigned int freq_hi_jiffies; int cpu; - unsigned int enable:1, - sample_type:1; + unsigned int sample_type:1; + /* + * percpu mutex that serializes governor limit change with + * do_dbs_timer invocation. We do not want do_dbs_timer to run + * when user is changing the governor or limits. + */ + struct mutex timer_mutex; }; static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info); @@ -79,9 +84,7 @@ static unsigned int dbs_enable; /* number of CPUs using this policy */ /* * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on - * different CPUs. It protects dbs_enable in governor start/stop. It also - * serializes governor limit_change with do_dbs_timer. We do not want - * do_dbs_timer to run when user is changing the governor or limits. + * different CPUs. It protects dbs_enable in governor start/stop. */ static DEFINE_MUTEX(dbs_mutex); @@ -187,13 +190,18 @@ static unsigned int powersave_bias_target(struct cpufreq_policy *policy, return freq_hi; } +static void ondemand_powersave_bias_init_cpu(int cpu) +{ + struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu); + dbs_info->freq_table = cpufreq_frequency_get_table(cpu); + dbs_info->freq_lo = 0; +} + static void ondemand_powersave_bias_init(void) { int i; for_each_online_cpu(i) { - struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, i); - dbs_info->freq_table = cpufreq_frequency_get_table(i); - dbs_info->freq_lo = 0; + ondemand_powersave_bias_init_cpu(i); } } @@ -235,12 +243,10 @@ static ssize_t store_sampling_rate(struct cpufreq_policy *unused, unsigned int input; int ret; ret = sscanf(buf, "%u", &input); + if (ret != 1) + return -EINVAL; mutex_lock(&dbs_mutex); - if (ret != 1) { - mutex_unlock(&dbs_mutex); - return -EINVAL; - } dbs_tuners_ins.sampling_rate = max(input, min_sampling_rate); mutex_unlock(&dbs_mutex); @@ -254,13 +260,12 @@ static ssize_t store_up_threshold(struct cpufreq_policy *unused, int ret; ret = sscanf(buf, "%u", &input); - mutex_lock(&dbs_mutex); if (ret != 1 || input > MAX_FREQUENCY_UP_THRESHOLD || input < MIN_FREQUENCY_UP_THRESHOLD) { - mutex_unlock(&dbs_mutex); return -EINVAL; } + mutex_lock(&dbs_mutex); dbs_tuners_ins.up_threshold = input; mutex_unlock(&dbs_mutex); @@ -358,9 +363,6 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) struct cpufreq_policy *policy; unsigned int j; - if (!this_dbs_info->enable) - return; - this_dbs_info->freq_lo = 0; policy = this_dbs_info->cur_policy; @@ -488,13 +490,7 @@ static void do_dbs_timer(struct work_struct *work) int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); delay -= jiffies % delay; - - mutex_lock(&dbs_mutex); - - if (!dbs_info->enable) { - mutex_unlock(&dbs_mutex); - return; - } + mutex_lock(&dbs_info->timer_mutex); /* Common NORMAL_SAMPLE setup */ dbs_info->sample_type = DBS_NORMAL_SAMPLE; @@ -511,7 +507,7 @@ static void do_dbs_timer(struct work_struct *work) dbs_info->freq_lo, CPUFREQ_RELATION_H); } queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay); - mutex_unlock(&dbs_mutex); + mutex_unlock(&dbs_info->timer_mutex); } static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) @@ -520,8 +516,6 @@ static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); delay -= jiffies % delay; - dbs_info->enable = 1; - ondemand_powersave_bias_init(); 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, @@ -530,7 +524,6 @@ static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) { - dbs_info->enable = 0; cancel_delayed_work_sync(&dbs_info->work); } @@ -549,19 +542,15 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, if ((!cpu_online(cpu)) || (!policy->cur)) return -EINVAL; - if (this_dbs_info->enable) /* Already enabled */ - break; - mutex_lock(&dbs_mutex); - dbs_enable++; rc = sysfs_create_group(&policy->kobj, &dbs_attr_group); if (rc) { - dbs_enable--; mutex_unlock(&dbs_mutex); return rc; } + dbs_enable++; for_each_cpu(j, policy->cpus) { struct cpu_dbs_info_s *j_dbs_info; j_dbs_info = &per_cpu(cpu_dbs_info, j); @@ -575,6 +564,8 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, } } this_dbs_info->cpu = cpu; + ondemand_powersave_bias_init_cpu(cpu); + mutex_init(&this_dbs_info->timer_mutex); /* * Start the timerschedule work, when this governor * is used for first time @@ -602,20 +593,21 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, mutex_lock(&dbs_mutex); sysfs_remove_group(&policy->kobj, &dbs_attr_group); + mutex_destroy(&this_dbs_info->timer_mutex); dbs_enable--; mutex_unlock(&dbs_mutex); break; case CPUFREQ_GOV_LIMITS: - mutex_lock(&dbs_mutex); + mutex_lock(&this_dbs_info->timer_mutex); if (policy->max < this_dbs_info->cur_policy->cur) __cpufreq_driver_target(this_dbs_info->cur_policy, 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); - mutex_unlock(&dbs_mutex); + mutex_unlock(&this_dbs_info->timer_mutex); break; } return 0; -- cgit v1.2.3-70-g09d2