[CPUFREQ] Add support to cpufreq_ondemand to ignore 'nice' cpu time

Signed-off-by: Alexander Clouter <alex-kernel@digriz.org.uk>
Signed-off-by: Dave Jones <davej@redhat.com>

1 files changed, 62 insertions, 4 deletions

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 84c658822a10..7d7244314ac9 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -78,6 +78,7 @@ struct dbs_tuners {
         unsigned int            sampling_down_factor;
         unsigned int            up_threshold;
         unsigned int            down_threshold;
+        unsigned int            ignore_nice;
 };
 
 static struct dbs_tuners dbs_tuners_ins = {
@@ -115,6 +116,7 @@ show_one(sampling_rate, sampling_rate);
 show_one(sampling_down_factor, sampling_down_factor);
 show_one(up_threshold, up_threshold);
 show_one(down_threshold, down_threshold);
+show_one(ignore_nice, ignore_nice);
 
 static ssize_t store_sampling_down_factor(struct cpufreq_policy *unused, 
                 const char *buf, size_t count)
@@ -193,6 +195,46 @@ static ssize_t store_down_threshold(struct cpufreq_policy *unused,
         return count;
 }
 
+static ssize_t store_ignore_nice(struct cpufreq_policy *policy,
+                const char *buf, size_t count)
+{
+        unsigned int input;
+        int ret;
+
+        unsigned int j;
+        
+        ret = sscanf (buf, "%u", &input);
+        if ( ret != 1 )
+                return -EINVAL;
+
+        if ( input > 1 )
+                input = 1;
+        
+        down(&dbs_sem);
+        if ( input == dbs_tuners_ins.ignore_nice ) { /* nothing to do */
+                up(&dbs_sem);
+                return count;
+        }
+        dbs_tuners_ins.ignore_nice = input;
+
+        /* we need to re-evaluate prev_cpu_idle_up and prev_cpu_idle_down */
+        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 =
+                        kstat_cpu(j).cpustat.idle +
+                        kstat_cpu(j).cpustat.iowait +
+                        ( !dbs_tuners_ins.ignore_nice
+                          ? kstat_cpu(j).cpustat.nice : 0 );
+                j_dbs_info->prev_cpu_idle_down = j_dbs_info->prev_cpu_idle_up;
+        }
+        up(&dbs_sem);
+
+        return count;
+}
+
 #define define_one_rw(_name) \
 static struct freq_attr _name = \
 __ATTR(_name, 0644, show_##_name, store_##_name)
@@ -201,6 +243,7 @@ define_one_rw(sampling_rate);
 define_one_rw(sampling_down_factor);
 define_one_rw(up_threshold);
 define_one_rw(down_threshold);
+define_one_rw(ignore_nice);
 
 static struct attribute * dbs_attributes[] = {
         &sampling_rate_max.attr,
@@ -209,6 +252,7 @@ static struct attribute * dbs_attributes[] = {
         &sampling_down_factor.attr,
         &up_threshold.attr,
         &down_threshold.attr,
+        &ignore_nice.attr,
         NULL
 };
 
@@ -253,6 +297,9 @@ static void dbs_check_cpu(int cpu)
         /* Check for frequency increase */
         total_idle_ticks = kstat_cpu(cpu).cpustat.idle +
                 kstat_cpu(cpu).cpustat.iowait;
+          /* consider 'nice' tasks as 'idle' time too if required */
+          if (dbs_tuners_ins.ignore_nice == 0)
+                total_idle_ticks += kstat_cpu(cpu).cpustat.nice;
         idle_ticks = total_idle_ticks -
                 this_dbs_info->prev_cpu_idle_up;
         this_dbs_info->prev_cpu_idle_up = total_idle_ticks;
@@ -269,6 +316,9 @@ static void dbs_check_cpu(int cpu)
                 /* Check for frequency increase */
                 total_idle_ticks = kstat_cpu(j).cpustat.idle +
                         kstat_cpu(j).cpustat.iowait;
+                  /* consider 'nice' too? */
+                  if (dbs_tuners_ins.ignore_nice == 0)
+                           total_idle_ticks += kstat_cpu(j).cpustat.nice;
                 tmp_idle_ticks = total_idle_ticks -
                         j_dbs_info->prev_cpu_idle_up;
                 j_dbs_info->prev_cpu_idle_up = total_idle_ticks;
@@ -297,6 +347,9 @@ static void dbs_check_cpu(int cpu)
 
         total_idle_ticks = kstat_cpu(cpu).cpustat.idle +
                 kstat_cpu(cpu).cpustat.iowait;
+          /* consider 'nice' too? */
+          if (dbs_tuners_ins.ignore_nice == 0)
+                  total_idle_ticks += kstat_cpu(cpu).cpustat.nice;
         idle_ticks = total_idle_ticks -
                 this_dbs_info->prev_cpu_idle_down;
         this_dbs_info->prev_cpu_idle_down = total_idle_ticks;
@@ -312,6 +365,9 @@ static void dbs_check_cpu(int cpu)
                 /* Check for frequency increase */
                 total_idle_ticks = kstat_cpu(j).cpustat.idle +
                         kstat_cpu(j).cpustat.iowait;
+                  /* consider 'nice' too? */
+                  if (dbs_tuners_ins.ignore_nice == 0)
+                        total_idle_ticks += kstat_cpu(j).cpustat.nice;
                 tmp_idle_ticks = total_idle_ticks -
                         j_dbs_info->prev_cpu_idle_down;
                 j_dbs_info->prev_cpu_idle_down = total_idle_ticks;
@@ -397,10 +453,11 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
                 
                         j_dbs_info->prev_cpu_idle_up = 
                                 kstat_cpu(j).cpustat.idle +
-                                kstat_cpu(j).cpustat.iowait;
-                        j_dbs_info->prev_cpu_idle_down = 
-                                kstat_cpu(j).cpustat.idle +
-                                kstat_cpu(j).cpustat.iowait;
+                                kstat_cpu(j).cpustat.iowait +
+                                ( !dbs_tuners_ins.ignore_nice
+                                  ? kstat_cpu(j).cpustat.nice : 0 );
+                        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);
@@ -420,6 +477,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
                         def_sampling_rate = (latency / 1000) *
                                         DEF_SAMPLING_RATE_LATENCY_MULTIPLIER;
                         dbs_tuners_ins.sampling_rate = def_sampling_rate;
+                        dbs_tuners_ins.ignore_nice = 0;
 
                         dbs_timer_init();
                 }