[CPUFREQ][3/6] cpufreq: get_cpu_idle_time() changes in ondemand for idle-microaccounting

Preparatory changes for doing idle micro-accounting in ondemand governor.
get_cpu_idle_time() gets extra parameter and returns idle time and also the
wall time that corresponds to the idle time measurement.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>

1 files changed, 15 insertions, 14 deletions

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index 42fcb146ba22..b935092aab21 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -94,13 +94,13 @@ static struct dbs_tuners {
         .powersave_bias = 0,
 };
 
-static inline cputime64_t get_cpu_idle_time(unsigned int cpu)
+static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
 {
         cputime64_t idle_time;
-        cputime64_t cur_jiffies;
+        cputime64_t cur_wall_time;
         cputime64_t busy_time;
 
-        cur_jiffies = jiffies64_to_cputime64(get_jiffies_64());
+        cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
         busy_time = cputime64_add(kstat_cpu(cpu).cpustat.user,
                         kstat_cpu(cpu).cpustat.system);
 
@@ -113,7 +113,10 @@ static inline cputime64_t get_cpu_idle_time(unsigned int cpu)
                                 kstat_cpu(cpu).cpustat.nice);
         }
 
-        idle_time = cputime64_sub(cur_jiffies, busy_time);
+        idle_time = cputime64_sub(cur_wall_time, busy_time);
+        if (wall)
+                *wall = cur_wall_time;
+
         return idle_time;
 }
 
@@ -277,8 +280,8 @@ static ssize_t store_ignore_nice_load(struct cpufreq_policy *policy,
         for_each_online_cpu(j) {
                 struct cpu_dbs_info_s *dbs_info;
                 dbs_info = &per_cpu(cpu_dbs_info, j);
-                dbs_info->prev_cpu_idle = get_cpu_idle_time(j);
-                dbs_info->prev_cpu_wall = get_jiffies_64();
+                dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
+                                                &dbs_info->prev_cpu_wall);
         }
         mutex_unlock(&dbs_mutex);
 
@@ -368,21 +371,19 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
                 int freq_avg;
 
                 j_dbs_info = &per_cpu(cpu_dbs_info, j);
-                cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
+
+                cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
+
                 wall_time = (unsigned int) cputime64_sub(cur_wall_time,
                                 j_dbs_info->prev_cpu_wall);
                 j_dbs_info->prev_cpu_wall = cur_wall_time;
 
-                cur_idle_time = get_cpu_idle_time(j);
                 idle_time = (unsigned int) cputime64_sub(cur_idle_time,
                                 j_dbs_info->prev_cpu_idle);
                 j_dbs_info->prev_cpu_idle = cur_idle_time;
 
-                if (unlikely(wall_time <= idle_time ||
-                             (cputime_to_msecs(wall_time) <
-                              dbs_tuners_ins.sampling_rate / (2 * 1000)))) {
+                if (unlikely(!wall_time || wall_time < idle_time))
                         continue;
-                }
 
                 load = 100 * (wall_time - idle_time) / wall_time;
 
@@ -531,8 +532,8 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
                         j_dbs_info = &per_cpu(cpu_dbs_info, j);
                         j_dbs_info->cur_policy = policy;
 
-                        j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j);
-                        j_dbs_info->prev_cpu_wall = get_jiffies_64();
+                        j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
+                                                &j_dbs_info->prev_cpu_wall);
                 }
                 this_dbs_info->cpu = cpu;
                 /*