cpufreq: governor: Keep single copy of information common to policy->cpus

Some information is common to all CPUs belonging to a policy, but are
kept on per-cpu basis. Lets keep that in another structure common to all
policy->cpus. That will make updates/reads to that less complex and less
error prone.

The memory for cpu_common_dbs_info is allocated/freed at INIT/EXIT, so
that it we don't reallocate it for STOP/START sequence. It will be also
be used (in next patch) while the governor is stopped and so must not be
freed that early.

Reviewed-and-tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/cpufreq_conservative.c b/drivers/cpufreq/cpufreq_conservative.c
index af47d32..d21c3cf 100644 (file)
--- a/drivers/cpufreq/cpufreq_conservative.c
+++ b/drivers/cpufreq/cpufreq_conservative.c
@@ -47,7 +47,7 @@ static inline unsigned int get_freq_target(struct cs_dbs_tuners *cs_tuners,
 static void cs_check_cpu(int cpu, unsigned int load)
 {
        struct cs_cpu_dbs_info_s *dbs_info = &per_cpu(cs_cpu_dbs_info, cpu);
-       struct cpufreq_policy *policy = dbs_info->cdbs.policy;
+       struct cpufreq_policy *policy = dbs_info->cdbs.shared->policy;
        struct dbs_data *dbs_data = policy->governor_data;
        struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
 
@@ -106,22 +106,24 @@ static void cs_dbs_timer(struct work_struct *work)
 {
        struct cs_cpu_dbs_info_s *dbs_info = container_of(work,
                        struct cs_cpu_dbs_info_s, cdbs.dwork.work);
-       unsigned int cpu = dbs_info->cdbs.policy->cpu;
+       struct cpufreq_policy *policy = dbs_info->cdbs.shared->policy;
+       unsigned int cpu = policy->cpu;
        struct cs_cpu_dbs_info_s *core_dbs_info = &per_cpu(cs_cpu_dbs_info,
                        cpu);
-       struct dbs_data *dbs_data = dbs_info->cdbs.policy->governor_data;
+       struct dbs_data *dbs_data = policy->governor_data;
        struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
        int delay = delay_for_sampling_rate(cs_tuners->sampling_rate);
        bool modify_all = true;
 
-       mutex_lock(&core_dbs_info->cdbs.timer_mutex);
-       if (!need_load_eval(&core_dbs_info->cdbs, cs_tuners->sampling_rate))
+       mutex_lock(&core_dbs_info->cdbs.shared->timer_mutex);
+       if (!need_load_eval(core_dbs_info->cdbs.shared,
+                           cs_tuners->sampling_rate))
                modify_all = false;
        else
                dbs_check_cpu(dbs_data, cpu);
 
-       gov_queue_work(dbs_data, dbs_info->cdbs.policy, delay, modify_all);
-       mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
+       gov_queue_work(dbs_data, policy, delay, modify_all);
+       mutex_unlock(&core_dbs_info->cdbs.shared->timer_mutex);
 }
 
 static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
@@ -135,7 +137,7 @@ static int dbs_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
        if (!dbs_info->enable)
                return 0;
 
-       policy = dbs_info->cdbs.policy;
+       policy = dbs_info->cdbs.shared->policy;
 
        /*
         * we only care if our internally tracked freq moves outside the 'valid'

diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index c0566f8..b01cb72 100644 (file)
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -35,7 +35,7 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
        struct cpu_dbs_info *cdbs = dbs_data->cdata->get_cpu_cdbs(cpu);
        struct od_dbs_tuners *od_tuners = dbs_data->tuners;
        struct cs_dbs_tuners *cs_tuners = dbs_data->tuners;
-       struct cpufreq_policy *policy;
+       struct cpufreq_policy *policy = cdbs->shared->policy;
        unsigned int sampling_rate;
        unsigned int max_load = 0;
        unsigned int ignore_nice;
@@ -60,8 +60,6 @@ void dbs_check_cpu(struct dbs_data *dbs_data, int cpu)
                ignore_nice = cs_tuners->ignore_nice_load;
        }
 
-       policy = cdbs->policy;
-
        /* Get Absolute Load */
        for_each_cpu(j, policy->cpus) {
                struct cpu_dbs_info *j_cdbs;
@@ -209,17 +207,18 @@ static inline void gov_cancel_work(struct dbs_data *dbs_data,
 }
 
 /* Will return if we need to evaluate cpu load again or not */
-bool need_load_eval(struct cpu_dbs_info *cdbs, unsigned int sampling_rate)
+bool need_load_eval(struct cpu_common_dbs_info *shared,
+                   unsigned int sampling_rate)
 {
-       if (policy_is_shared(cdbs->policy)) {
+       if (policy_is_shared(shared->policy)) {
                ktime_t time_now = ktime_get();
-               s64 delta_us = ktime_us_delta(time_now, cdbs->time_stamp);
+               s64 delta_us = ktime_us_delta(time_now, shared->time_stamp);
 
                /* Do nothing if we recently have sampled */
                if (delta_us < (s64)(sampling_rate / 2))
                        return false;
                else
-                       cdbs->time_stamp = time_now;
+                       shared->time_stamp = time_now;
        }
 
        return true;
@@ -238,6 +237,37 @@ static void set_sampling_rate(struct dbs_data *dbs_data,
        }
 }
 
+static int alloc_common_dbs_info(struct cpufreq_policy *policy,
+                                struct common_dbs_data *cdata)
+{
+       struct cpu_common_dbs_info *shared;
+       int j;
+
+       /* Allocate memory for the common information for policy->cpus */
+       shared = kzalloc(sizeof(*shared), GFP_KERNEL);
+       if (!shared)
+               return -ENOMEM;
+
+       /* Set shared for all CPUs, online+offline */
+       for_each_cpu(j, policy->related_cpus)
+               cdata->get_cpu_cdbs(j)->shared = shared;
+
+       return 0;
+}
+
+static void free_common_dbs_info(struct cpufreq_policy *policy,
+                                struct common_dbs_data *cdata)
+{
+       struct cpu_dbs_info *cdbs = cdata->get_cpu_cdbs(policy->cpu);
+       struct cpu_common_dbs_info *shared = cdbs->shared;
+       int j;
+
+       for_each_cpu(j, policy->cpus)
+               cdata->get_cpu_cdbs(j)->shared = NULL;
+
+       kfree(shared);
+}
+
 static int cpufreq_governor_init(struct cpufreq_policy *policy,
                                 struct dbs_data *dbs_data,
                                 struct common_dbs_data *cdata)
@@ -248,6 +278,11 @@ static int cpufreq_governor_init(struct cpufreq_policy *policy,
        if (dbs_data) {
                if (WARN_ON(have_governor_per_policy()))
                        return -EINVAL;
+
+               ret = alloc_common_dbs_info(policy, cdata);
+               if (ret)
+                       return ret;
+
                dbs_data->usage_count++;
                policy->governor_data = dbs_data;
                return 0;
@@ -257,12 +292,16 @@ static int cpufreq_governor_init(struct cpufreq_policy *policy,
        if (!dbs_data)
                return -ENOMEM;
 
+       ret = alloc_common_dbs_info(policy, cdata);
+       if (ret)
+               goto free_dbs_data;
+
        dbs_data->cdata = cdata;
        dbs_data->usage_count = 1;
 
        ret = cdata->init(dbs_data, !policy->governor->initialized);
        if (ret)
-               goto free_dbs_data;
+               goto free_common_dbs_info;
 
        /* policy latency is in ns. Convert it to us first */
        latency = policy->cpuinfo.transition_latency / 1000;
@@ -299,6 +338,8 @@ put_kobj:
        }
 cdata_exit:
        cdata->exit(dbs_data, !policy->governor->initialized);
+free_common_dbs_info:
+       free_common_dbs_info(policy, cdata);
 free_dbs_data:
        kfree(dbs_data);
        return ret;
@@ -322,6 +363,8 @@ static void cpufreq_governor_exit(struct cpufreq_policy *policy,
                cdata->exit(dbs_data, policy->governor->initialized == 1);
                kfree(dbs_data);
        }
+
+       free_common_dbs_info(policy, cdata);
 }
 
 static int cpufreq_governor_start(struct cpufreq_policy *policy,
@@ -330,6 +373,7 @@ static int cpufreq_governor_start(struct cpufreq_policy *policy,
        struct common_dbs_data *cdata = dbs_data->cdata;
        unsigned int sampling_rate, ignore_nice, j, cpu = policy->cpu;
        struct cpu_dbs_info *cdbs = cdata->get_cpu_cdbs(cpu);
+       struct cpu_common_dbs_info *shared = cdbs->shared;
        int io_busy = 0;
 
        if (!policy->cur)
@@ -348,11 +392,14 @@ static int cpufreq_governor_start(struct cpufreq_policy *policy,
                io_busy = od_tuners->io_is_busy;
        }
 
+       shared->policy = policy;
+       shared->time_stamp = ktime_get();
+       mutex_init(&shared->timer_mutex);
+
        for_each_cpu(j, policy->cpus) {
                struct cpu_dbs_info *j_cdbs = cdata->get_cpu_cdbs(j);
                unsigned int prev_load;
 
-               j_cdbs->policy = policy;
                j_cdbs->prev_cpu_idle =
                        get_cpu_idle_time(j, &j_cdbs->prev_cpu_wall, io_busy);
 
@@ -364,7 +411,6 @@ static int cpufreq_governor_start(struct cpufreq_policy *policy,
                if (ignore_nice)
                        j_cdbs->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE];
 
-               mutex_init(&j_cdbs->timer_mutex);
                INIT_DEFERRABLE_WORK(&j_cdbs->dwork, cdata->gov_dbs_timer);
        }
 
@@ -384,9 +430,6 @@ static int cpufreq_governor_start(struct cpufreq_policy *policy,
                od_ops->powersave_bias_init_cpu(cpu);
        }
 
-       /* Initiate timer time stamp */
-       cdbs->time_stamp = ktime_get();
-
        gov_queue_work(dbs_data, policy, delay_for_sampling_rate(sampling_rate),
                       true);
        return 0;
@@ -398,6 +441,9 @@ static void cpufreq_governor_stop(struct cpufreq_policy *policy,
        struct common_dbs_data *cdata = dbs_data->cdata;
        unsigned int cpu = policy->cpu;
        struct cpu_dbs_info *cdbs = cdata->get_cpu_cdbs(cpu);
+       struct cpu_common_dbs_info *shared = cdbs->shared;
+
+       gov_cancel_work(dbs_data, policy);
 
        if (cdata->governor == GOV_CONSERVATIVE) {
                struct cs_cpu_dbs_info_s *cs_dbs_info =
@@ -406,10 +452,8 @@ static void cpufreq_governor_stop(struct cpufreq_policy *policy,
                cs_dbs_info->enable = 0;
        }
 
-       gov_cancel_work(dbs_data, policy);
-
-       mutex_destroy(&cdbs->timer_mutex);
-       cdbs->policy = NULL;
+       shared->policy = NULL;
+       mutex_destroy(&shared->timer_mutex);
 }
 
 static void cpufreq_governor_limits(struct cpufreq_policy *policy,
@@ -419,18 +463,18 @@ static void cpufreq_governor_limits(struct cpufreq_policy *policy,
        unsigned int cpu = policy->cpu;
        struct cpu_dbs_info *cdbs = cdata->get_cpu_cdbs(cpu);
 
-       if (!cdbs->policy)
+       if (!cdbs->shared || !cdbs->shared->policy)
                return;
 
-       mutex_lock(&cdbs->timer_mutex);
-       if (policy->max < cdbs->policy->cur)
-               __cpufreq_driver_target(cdbs->policy, policy->max,
+       mutex_lock(&cdbs->shared->timer_mutex);
+       if (policy->max < cdbs->shared->policy->cur)
+               __cpufreq_driver_target(cdbs->shared->policy, policy->max,
                                        CPUFREQ_RELATION_H);
-       else if (policy->min > cdbs->policy->cur)
-               __cpufreq_driver_target(cdbs->policy, policy->min,
+       else if (policy->min > cdbs->shared->policy->cur)
+               __cpufreq_driver_target(cdbs->shared->policy, policy->min,
                                        CPUFREQ_RELATION_L);
        dbs_check_cpu(dbs_data, cpu);
-       mutex_unlock(&cdbs->timer_mutex);
+       mutex_unlock(&cdbs->shared->timer_mutex);
 }
 
 int cpufreq_governor_dbs(struct cpufreq_policy *policy,

diff --git a/drivers/cpufreq/cpufreq_governor.h b/drivers/cpufreq/cpufreq_governor.h
index a0f8eb7..8e4a25f 100644 (file)
--- a/drivers/cpufreq/cpufreq_governor.h
+++ b/drivers/cpufreq/cpufreq_governor.h
@@ -128,6 +128,18 @@ static void *get_cpu_dbs_info_s(int cpu)                           \
  * cs_*: Conservative governor
  */
 
+/* Common to all CPUs of a policy */
+struct cpu_common_dbs_info {
+       struct cpufreq_policy *policy;
+       /*
+        * percpu mutex that serializes governor limit change with gov_dbs_timer
+        * invocation. We do not want gov_dbs_timer to run when user is changing
+        * the governor or limits.
+        */
+       struct mutex timer_mutex;
+       ktime_t time_stamp;
+};
+
 /* Per cpu structures */
 struct cpu_dbs_info {
        u64 prev_cpu_idle;
@@ -140,15 +152,8 @@ struct cpu_dbs_info {
         * wake-up from idle.
         */
        unsigned int prev_load;
-       struct cpufreq_policy *policy;
        struct delayed_work dwork;
-       /*
-        * percpu mutex that serializes governor limit change with gov_dbs_timer
-        * invocation. We do not want gov_dbs_timer to run when user is changing
-        * the governor or limits.
-        */
-       struct mutex timer_mutex;
-       ktime_t time_stamp;
+       struct cpu_common_dbs_info *shared;
 };
 
 struct od_cpu_dbs_info_s {
@@ -264,7 +269,8 @@ static ssize_t show_sampling_rate_min_gov_pol                               \
 extern struct mutex cpufreq_governor_lock;
 
 void dbs_check_cpu(struct dbs_data *dbs_data, int cpu);
-bool need_load_eval(struct cpu_dbs_info *cdbs, unsigned int sampling_rate);
+bool need_load_eval(struct cpu_common_dbs_info *shared,
+                   unsigned int sampling_rate);
 int cpufreq_governor_dbs(struct cpufreq_policy *policy,
                struct common_dbs_data *cdata, unsigned int event);
 void gov_queue_work(struct dbs_data *dbs_data, struct cpufreq_policy *policy,

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index d29c6f9..14d7e86 100644 (file)
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -155,7 +155,7 @@ static void dbs_freq_increase(struct cpufreq_policy *policy, unsigned int freq)
 static void od_check_cpu(int cpu, unsigned int load)
 {
        struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
-       struct cpufreq_policy *policy = dbs_info->cdbs.policy;
+       struct cpufreq_policy *policy = dbs_info->cdbs.shared->policy;
        struct dbs_data *dbs_data = policy->governor_data;
        struct od_dbs_tuners *od_tuners = dbs_data->tuners;
 
@@ -195,16 +195,18 @@ static void od_dbs_timer(struct work_struct *work)
 {
        struct od_cpu_dbs_info_s *dbs_info =
                container_of(work, struct od_cpu_dbs_info_s, cdbs.dwork.work);
-       unsigned int cpu = dbs_info->cdbs.policy->cpu;
+       struct cpufreq_policy *policy = dbs_info->cdbs.shared->policy;
+       unsigned int cpu = policy->cpu;
        struct od_cpu_dbs_info_s *core_dbs_info = &per_cpu(od_cpu_dbs_info,
                        cpu);
-       struct dbs_data *dbs_data = dbs_info->cdbs.policy->governor_data;
+       struct dbs_data *dbs_data = policy->governor_data;
        struct od_dbs_tuners *od_tuners = dbs_data->tuners;
        int delay = 0, sample_type = core_dbs_info->sample_type;
        bool modify_all = true;
 
-       mutex_lock(&core_dbs_info->cdbs.timer_mutex);
-       if (!need_load_eval(&core_dbs_info->cdbs, od_tuners->sampling_rate)) {
+       mutex_lock(&core_dbs_info->cdbs.shared->timer_mutex);
+       if (!need_load_eval(core_dbs_info->cdbs.shared,
+                           od_tuners->sampling_rate)) {
                modify_all = false;
                goto max_delay;
        }
@@ -213,8 +215,7 @@ static void od_dbs_timer(struct work_struct *work)
        core_dbs_info->sample_type = OD_NORMAL_SAMPLE;
        if (sample_type == OD_SUB_SAMPLE) {
                delay = core_dbs_info->freq_lo_jiffies;
-               __cpufreq_driver_target(core_dbs_info->cdbs.policy,
-                                       core_dbs_info->freq_lo,
+               __cpufreq_driver_target(policy, core_dbs_info->freq_lo,
                                        CPUFREQ_RELATION_H);
        } else {
                dbs_check_cpu(dbs_data, cpu);
@@ -230,8 +231,8 @@ max_delay:
                delay = delay_for_sampling_rate(od_tuners->sampling_rate
                                * core_dbs_info->rate_mult);
 
-       gov_queue_work(dbs_data, dbs_info->cdbs.policy, delay, modify_all);
-       mutex_unlock(&core_dbs_info->cdbs.timer_mutex);
+       gov_queue_work(dbs_data, policy, delay, modify_all);
+       mutex_unlock(&core_dbs_info->cdbs.shared->timer_mutex);
 }
 
 /************************** sysfs interface ************************/
@@ -274,10 +275,10 @@ static void update_sampling_rate(struct dbs_data *dbs_data,
                dbs_info = &per_cpu(od_cpu_dbs_info, cpu);
                cpufreq_cpu_put(policy);
 
-               mutex_lock(&dbs_info->cdbs.timer_mutex);
+               mutex_lock(&dbs_info->cdbs.shared->timer_mutex);
 
                if (!delayed_work_pending(&dbs_info->cdbs.dwork)) {
-                       mutex_unlock(&dbs_info->cdbs.timer_mutex);
+                       mutex_unlock(&dbs_info->cdbs.shared->timer_mutex);
                        continue;
                }
 
@@ -286,15 +287,15 @@ static void update_sampling_rate(struct dbs_data *dbs_data,
 
                if (time_before(next_sampling, appointed_at)) {
 
-                       mutex_unlock(&dbs_info->cdbs.timer_mutex);
+                       mutex_unlock(&dbs_info->cdbs.shared->timer_mutex);
                        cancel_delayed_work_sync(&dbs_info->cdbs.dwork);
-                       mutex_lock(&dbs_info->cdbs.timer_mutex);
+                       mutex_lock(&dbs_info->cdbs.shared->timer_mutex);
 
-                       gov_queue_work(dbs_data, dbs_info->cdbs.policy,
+                       gov_queue_work(dbs_data, policy,
                                       usecs_to_jiffies(new_rate), true);
 
                }
-               mutex_unlock(&dbs_info->cdbs.timer_mutex);
+               mutex_unlock(&dbs_info->cdbs.shared->timer_mutex);
        }
 }
 
@@ -557,13 +558,16 @@ static void od_set_powersave_bias(unsigned int powersave_bias)
 
        get_online_cpus();
        for_each_online_cpu(cpu) {
+               struct cpu_common_dbs_info *shared;
+
                if (cpumask_test_cpu(cpu, &done))
                        continue;
 
-               policy = per_cpu(od_cpu_dbs_info, cpu).cdbs.policy;
-               if (!policy)
+               shared = per_cpu(od_cpu_dbs_info, cpu).cdbs.shared;
+               if (!shared)
                        continue;
 
+               policy = shared->policy;
                cpumask_or(&done, &done, policy->cpus);
 
                if (policy->governor != &cpufreq_gov_ondemand)