From c120069779e3e35917c15393cf2847fa79811eb6 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Mon, 5 Feb 2007 16:12:43 -0800 Subject: [CPUFREQ] Remove hotplug cpu crap The hotplug CPU locking in cpufreq is horrendous. No-one seems to care enough to fix it, so just remove it so that the 99.9% of the real world users of this code can use cpufreq without being bothered by warnings. Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- drivers/cpufreq/cpufreq_ondemand.c | 2 -- 1 file changed, 2 deletions(-) (limited to 'drivers/cpufreq/cpufreq_ondemand.c') diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index f697449327c6..d52f9b426521 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -440,9 +440,7 @@ static void do_dbs_timer(struct work_struct *work) dbs_info->sample_type = DBS_NORMAL_SAMPLE; if (!dbs_tuners_ins.powersave_bias || sample_type == DBS_NORMAL_SAMPLE) { - lock_cpu_hotplug(); dbs_check_cpu(dbs_info); - unlock_cpu_hotplug(); if (dbs_info->freq_lo) { /* Setup timer for SUB_SAMPLE */ dbs_info->sample_type = DBS_SUB_SAMPLE; -- cgit v1.2.2 From 529af7a14f04f92213bac371931a2b2b060c63fa Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Mon, 5 Feb 2007 16:12:44 -0800 Subject: [CPUFREQ] ondemand governor restructure the work callback Restructure the delayed_work callback in ondemand. This eliminates the need for smp_processor_id in the callback function and also helps in proper locking and avoiding flush_workqueue when stopping the governor (done in subsequent patch). Signed-off-by: Venkatesh Pallipadi Cc: Gautham R Shenoy Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- drivers/cpufreq/cpufreq_ondemand.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) (limited to 'drivers/cpufreq/cpufreq_ondemand.c') diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index d52f9b426521..a480834c9627 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -52,19 +52,20 @@ static unsigned int def_sampling_rate; static void do_dbs_timer(struct work_struct *work); /* Sampling types */ -enum dbs_sample {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE}; +enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE}; struct cpu_dbs_info_s { cputime64_t prev_cpu_idle; cputime64_t prev_cpu_wall; struct cpufreq_policy *cur_policy; struct delayed_work work; - enum dbs_sample sample_type; - unsigned int enable; 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; }; static DEFINE_PER_CPU(struct cpu_dbs_info_s, cpu_dbs_info); @@ -402,7 +403,7 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) if (load < (dbs_tuners_ins.up_threshold - 10)) { unsigned int freq_next, freq_cur; - freq_cur = cpufreq_driver_getavg(policy); + freq_cur = __cpufreq_driver_getavg(policy); if (!freq_cur) freq_cur = policy->cur; @@ -423,9 +424,11 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) static void do_dbs_timer(struct work_struct *work) { - unsigned int cpu = smp_processor_id(); - struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu); - enum dbs_sample sample_type = dbs_info->sample_type; + struct cpu_dbs_info_s *dbs_info = + container_of(work, struct cpu_dbs_info_s, work.work); + unsigned int cpu = dbs_info->cpu; + int sample_type = dbs_info->sample_type; + /* We want all CPUs to do sampling nearly on same jiffy */ int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); @@ -454,17 +457,17 @@ static void do_dbs_timer(struct work_struct *work) queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay); } -static inline void dbs_timer_init(unsigned int cpu) +static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) { - struct cpu_dbs_info_s *dbs_info = &per_cpu(cpu_dbs_info, cpu); /* We want all CPUs to do sampling nearly on same jiffy */ int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); delay -= jiffies % delay; ondemand_powersave_bias_init(); - INIT_DELAYED_WORK_NAR(&dbs_info->work, do_dbs_timer); dbs_info->sample_type = DBS_NORMAL_SAMPLE; - queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay); + INIT_DELAYED_WORK_NAR(&dbs_info->work, do_dbs_timer); + queue_delayed_work_on(dbs_info->cpu, kondemand_wq, &dbs_info->work, + delay); } static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) @@ -528,6 +531,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j); j_dbs_info->prev_cpu_wall = get_jiffies_64(); } + this_dbs_info->cpu = cpu; this_dbs_info->enable = 1; /* * Start the timerschedule work, when this governor @@ -548,7 +552,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, dbs_tuners_ins.sampling_rate = def_sampling_rate; } - dbs_timer_init(policy->cpu); + dbs_timer_init(this_dbs_info); mutex_unlock(&dbs_mutex); break; -- cgit v1.2.2 From 56463b78cdca8e9ff8cc1759bca0c0777a061d6b Mon Sep 17 00:00:00 2001 From: Venkatesh Pallipadi Date: Mon, 5 Feb 2007 16:12:45 -0800 Subject: [CPUFREQ] ondemand governor use new cpufreq rwsem locking in work callback Eliminate flush_workqueue in cpufreq_governor(STOP) callpath. Using flush there has a deadlock potential as in http://uwsg.iu.edu/hypermail/linux/kernel/0611.3/1223.html Also, cleanup the locking issues with do_dbs_timer delayed_work callback. As it changes the CPU frequency using __cpufreq_target, it needs to have policy_rwsem in write mode, which also protects it from hot plug. Signed-off-by: Venkatesh Pallipadi Cc: Gautham R Shenoy Signed-off-by: Andrew Morton Signed-off-by: Dave Jones --- drivers/cpufreq/cpufreq_ondemand.c | 34 ++++++++++++++++------------------ 1 file changed, 16 insertions(+), 18 deletions(-) (limited to 'drivers/cpufreq/cpufreq_ondemand.c') diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index a480834c9627..bcf8bb877a8b 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -437,8 +437,14 @@ static void do_dbs_timer(struct work_struct *work) delay -= jiffies % delay; - if (!dbs_info->enable) + if (lock_policy_rwsem_write(cpu) < 0) return; + + if (!dbs_info->enable) { + unlock_policy_rwsem_write(cpu); + return; + } + /* Common NORMAL_SAMPLE setup */ dbs_info->sample_type = DBS_NORMAL_SAMPLE; if (!dbs_tuners_ins.powersave_bias || @@ -455,6 +461,7 @@ static void do_dbs_timer(struct work_struct *work) CPUFREQ_RELATION_H); } queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay); + unlock_policy_rwsem_write(cpu); } static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info) @@ -463,6 +470,7 @@ 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_NAR(&dbs_info->work, do_dbs_timer); @@ -474,7 +482,6 @@ static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) { dbs_info->enable = 0; cancel_delayed_work(&dbs_info->work); - flush_workqueue(kondemand_wq); } static int cpufreq_governor_dbs(struct cpufreq_policy *policy, @@ -503,21 +510,9 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, mutex_lock(&dbs_mutex); dbs_enable++; - if (dbs_enable == 1) { - kondemand_wq = create_workqueue("kondemand"); - if (!kondemand_wq) { - printk(KERN_ERR - "Creation of kondemand failed\n"); - dbs_enable--; - mutex_unlock(&dbs_mutex); - return -ENOSPC; - } - } rc = sysfs_create_group(&policy->kobj, &dbs_attr_group); if (rc) { - if (dbs_enable == 1) - destroy_workqueue(kondemand_wq); dbs_enable--; mutex_unlock(&dbs_mutex); return rc; @@ -532,7 +527,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, j_dbs_info->prev_cpu_wall = get_jiffies_64(); } this_dbs_info->cpu = cpu; - this_dbs_info->enable = 1; /* * Start the timerschedule work, when this governor * is used for first time @@ -562,9 +556,6 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, dbs_timer_exit(this_dbs_info); sysfs_remove_group(&policy->kobj, &dbs_attr_group); dbs_enable--; - if (dbs_enable == 0) - destroy_workqueue(kondemand_wq); - mutex_unlock(&dbs_mutex); break; @@ -593,12 +584,18 @@ static struct cpufreq_governor cpufreq_gov_dbs = { static int __init cpufreq_gov_dbs_init(void) { + kondemand_wq = create_workqueue("kondemand"); + if (!kondemand_wq) { + printk(KERN_ERR "Creation of kondemand failed\n"); + return -EFAULT; + } return cpufreq_register_governor(&cpufreq_gov_dbs); } static void __exit cpufreq_gov_dbs_exit(void) { cpufreq_unregister_governor(&cpufreq_gov_dbs); + destroy_workqueue(kondemand_wq); } @@ -610,3 +607,4 @@ MODULE_LICENSE("GPL"); module_init(cpufreq_gov_dbs_init); module_exit(cpufreq_gov_dbs_exit); + -- cgit v1.2.2 From c18a1483f478adbeb4cc7148db22c4a9c10aaee3 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Sat, 10 Feb 2007 20:03:51 -0500 Subject: [CPUFREQ] Whitespace fixup Signed-off-by: Dave Jones --- drivers/cpufreq/cpufreq_ondemand.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/cpufreq/cpufreq_ondemand.c') diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index bcf8bb877a8b..d60bcb9d14cc 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -470,7 +470,7 @@ 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; + dbs_info->enable = 1; ondemand_powersave_bias_init(); dbs_info->sample_type = DBS_NORMAL_SAMPLE; INIT_DELAYED_WORK_NAR(&dbs_info->work, do_dbs_timer); -- cgit v1.2.2