Userspace governor has got more code than what it needs for its functioning. Lets simplify it.
Over that it will fix issues in cpufreq_governor_userspace(), which isn't doing right things in START/STOP. It is working per-cpu currently whereas it just required to manage policy->cpu.
Reported-by: Xiaoguang Chen chenxg.marvell@gmail.com Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- @Rafael:
I don't know why this code was initially added. Please let me know if I am doing something stupid.
Also, please apply it as a fix for 3.10 as it is broken recently in 3.9.
drivers/cpufreq/cpufreq_userspace.c | 108 ++++-------------------------------- 1 file changed, 12 insertions(+), 96 deletions(-)
diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c index bbeb9c0..5dc77b7 100644 --- a/drivers/cpufreq/cpufreq_userspace.c +++ b/drivers/cpufreq/cpufreq_userspace.c @@ -13,55 +13,13 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/smp.h> -#include <linux/init.h> -#include <linux/spinlock.h> -#include <linux/interrupt.h> #include <linux/cpufreq.h> -#include <linux/cpu.h> -#include <linux/types.h> -#include <linux/fs.h> -#include <linux/sysfs.h> +#include <linux/init.h> +#include <linux/module.h> #include <linux/mutex.h>
-/** - * A few values needed by the userspace governor - */ -static DEFINE_PER_CPU(unsigned int, cpu_max_freq); -static DEFINE_PER_CPU(unsigned int, cpu_min_freq); -static DEFINE_PER_CPU(unsigned int, cpu_cur_freq); /* current CPU freq */ -static DEFINE_PER_CPU(unsigned int, cpu_set_freq); /* CPU freq desired by - userspace */ static DEFINE_PER_CPU(unsigned int, cpu_is_managed); - static DEFINE_MUTEX(userspace_mutex); -static int cpus_using_userspace_governor; - -/* keep track of frequency transitions */ -static int -userspace_cpufreq_notifier(struct notifier_block *nb, unsigned long val, - void *data) -{ - struct cpufreq_freqs *freq = data; - - if (!per_cpu(cpu_is_managed, freq->cpu)) - return 0; - - if (val == CPUFREQ_POSTCHANGE) { - pr_debug("saving cpu_cur_freq of cpu %u to be %u kHz\n", - freq->cpu, freq->new); - per_cpu(cpu_cur_freq, freq->cpu) = freq->new; - } - - return 0; -} - -static struct notifier_block userspace_cpufreq_notifier_block = { - .notifier_call = userspace_cpufreq_notifier -}; -
/** * cpufreq_set - set the CPU frequency @@ -80,13 +38,6 @@ static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq) if (!per_cpu(cpu_is_managed, policy->cpu)) goto err;
- per_cpu(cpu_set_freq, policy->cpu) = freq; - - if (freq < per_cpu(cpu_min_freq, policy->cpu)) - freq = per_cpu(cpu_min_freq, policy->cpu); - if (freq > per_cpu(cpu_max_freq, policy->cpu)) - freq = per_cpu(cpu_max_freq, policy->cpu); - /* * We're safe from concurrent calls to ->target() here * as we hold the userspace_mutex lock. If we were calling @@ -107,7 +58,7 @@ static int cpufreq_set(struct cpufreq_policy *policy, unsigned int freq)
static ssize_t show_speed(struct cpufreq_policy *policy, char *buf) { - return sprintf(buf, "%u\n", per_cpu(cpu_cur_freq, policy->cpu)); + return sprintf(buf, "%u\n", policy->cur); }
static int cpufreq_governor_userspace(struct cpufreq_policy *policy, @@ -119,66 +70,31 @@ static int cpufreq_governor_userspace(struct cpufreq_policy *policy, switch (event) { case CPUFREQ_GOV_START: BUG_ON(!policy->cur); - mutex_lock(&userspace_mutex); - - if (cpus_using_userspace_governor == 0) { - cpufreq_register_notifier( - &userspace_cpufreq_notifier_block, - CPUFREQ_TRANSITION_NOTIFIER); - } - cpus_using_userspace_governor++; + pr_debug("started managing cpu %u\n", cpu);
+ mutex_lock(&userspace_mutex); per_cpu(cpu_is_managed, cpu) = 1; - per_cpu(cpu_min_freq, cpu) = policy->min; - per_cpu(cpu_max_freq, cpu) = policy->max; - per_cpu(cpu_cur_freq, cpu) = policy->cur; - per_cpu(cpu_set_freq, cpu) = policy->cur; - pr_debug("managing cpu %u started " - "(%u - %u kHz, currently %u kHz)\n", - cpu, - per_cpu(cpu_min_freq, cpu), - per_cpu(cpu_max_freq, cpu), - per_cpu(cpu_cur_freq, cpu)); - mutex_unlock(&userspace_mutex); break; case CPUFREQ_GOV_STOP: - mutex_lock(&userspace_mutex); - cpus_using_userspace_governor--; - if (cpus_using_userspace_governor == 0) { - cpufreq_unregister_notifier( - &userspace_cpufreq_notifier_block, - CPUFREQ_TRANSITION_NOTIFIER); - } + pr_debug("managing cpu %u stopped\n", cpu);
+ mutex_lock(&userspace_mutex); per_cpu(cpu_is_managed, cpu) = 0; - per_cpu(cpu_min_freq, cpu) = 0; - per_cpu(cpu_max_freq, cpu) = 0; - per_cpu(cpu_set_freq, cpu) = 0; - pr_debug("managing cpu %u stopped\n", cpu); mutex_unlock(&userspace_mutex); break; case CPUFREQ_GOV_LIMITS: mutex_lock(&userspace_mutex); - pr_debug("limit event for cpu %u: %u - %u kHz, " - "currently %u kHz, last set to %u kHz\n", + pr_debug("limit event for cpu %u: %u - %u kHz, currently %u kHz\n", cpu, policy->min, policy->max, - per_cpu(cpu_cur_freq, cpu), - per_cpu(cpu_set_freq, cpu)); - if (policy->max < per_cpu(cpu_set_freq, cpu)) { + policy->cur); + + if (policy->max < policy->cur) __cpufreq_driver_target(policy, policy->max, CPUFREQ_RELATION_H); - } else if (policy->min > per_cpu(cpu_set_freq, cpu)) { + else if (policy->min > policy->cur) __cpufreq_driver_target(policy, policy->min, CPUFREQ_RELATION_L); - } else { - __cpufreq_driver_target(policy, - per_cpu(cpu_set_freq, cpu), - CPUFREQ_RELATION_L); - } - per_cpu(cpu_min_freq, cpu) = policy->min; - per_cpu(cpu_max_freq, cpu) = policy->max; - per_cpu(cpu_cur_freq, cpu) = policy->cur; mutex_unlock(&userspace_mutex); break; }