[CPUFREQ] Make ignore_nice_load setting of ondemand work as expected.

ondemand micro-accounting of idle time changes broke ignore_nice_load
sysfs setting due to a thinko in the code.

The bug entry:
http://bugzilla.kernel.org/show_bug.cgi?id=12310

Reported-by: Jim Bray <jimsantelmo@gmail.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 6a2b036..6f45b16 100644 (file)
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -117,11 +117,7 @@ static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu,
        busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.irq);
        busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.softirq);
        busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.steal);
-
-       if (!dbs_tuners_ins.ignore_nice) {
-               busy_time = cputime64_add(busy_time,
-                               kstat_cpu(cpu).cpustat.nice);
-       }
+       busy_time = cputime64_add(busy_time, kstat_cpu(cpu).cpustat.nice);
 
        idle_time = cputime64_sub(cur_wall_time, busy_time);
        if (wall)
@@ -137,23 +133,6 @@ static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
        if (idle_time == -1ULL)
                return get_cpu_idle_time_jiffy(cpu, wall);
 
-       if (dbs_tuners_ins.ignore_nice) {
-               cputime64_t cur_nice;
-               unsigned long cur_nice_jiffies;
-               struct cpu_dbs_info_s *dbs_info;
-
-               dbs_info = &per_cpu(cpu_dbs_info, cpu);
-               cur_nice = cputime64_sub(kstat_cpu(cpu).cpustat.nice,
-                                        dbs_info->prev_cpu_nice);
-               /*
-                * Assumption: nice time between sampling periods will be
-                * less than 2^32 jiffies for 32 bit sys
-                */
-               cur_nice_jiffies = (unsigned long)
-                                       cputime64_to_jiffies64(cur_nice);
-               dbs_info->prev_cpu_nice = kstat_cpu(cpu).cpustat.nice;
-               return idle_time + jiffies_to_usecs(cur_nice_jiffies);
-       }
        return idle_time;
 }
 
@@ -319,6 +298,9 @@ static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy,
                dbs_info = &per_cpu(cpu_dbs_info, j);
                dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
                                                &dbs_info->prev_cpu_wall);
+               if (dbs_tuners_ins.ignore_nice)
+                       dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice;
+
        }
        mutex_unlock(&dbs_mutex);
 
@@ -419,6 +401,23 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
                                j_dbs_info->prev_cpu_idle);
                j_dbs_info->prev_cpu_idle = cur_idle_time;
 
+               if (dbs_tuners_ins.ignore_nice) {
+                       cputime64_t cur_nice;
+                       unsigned long cur_nice_jiffies;
+
+                       cur_nice = cputime64_sub(kstat_cpu(j).cpustat.nice,
+                                        j_dbs_info->prev_cpu_nice);
+                       /*
+                        * Assumption: nice time between sampling periods will
+                        * be less than 2^32 jiffies for 32 bit sys
+                        */
+                       cur_nice_jiffies = (unsigned long)
+                                       cputime64_to_jiffies64(cur_nice);
+
+                       j_dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice;
+                       idle_time += jiffies_to_usecs(cur_nice_jiffies);
+               }
+
                if (unlikely(!wall_time || wall_time < idle_time))
                        continue;
 
@@ -575,6 +574,10 @@ 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);
+                       if (dbs_tuners_ins.ignore_nice) {
+                               j_dbs_info->prev_cpu_nice =
+                                               kstat_cpu(j).cpustat.nice;
+                       }
                }
                this_dbs_info->cpu = cpu;
                /*