[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>

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 84c658822a105393801b01d243dbb6b719593c52..7d7244314ac9a4d55e78d9427102dbe7ab59366a 100644 (file)
--- 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();
                }