1 files changed, 28 insertions, 2 deletions

diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
index bd444dc93cf2..ed472f8dfb72 100644
--- a/drivers/cpufreq/cpufreq_ondemand.c
+++ b/drivers/cpufreq/cpufreq_ondemand.c
@@ -73,6 +73,7 @@ enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE};
 
 struct cpu_dbs_info_s {
         cputime64_t prev_cpu_idle;
+        cputime64_t prev_cpu_iowait;
         cputime64_t prev_cpu_wall;
         cputime64_t prev_cpu_nice;
         struct cpufreq_policy *cur_policy;
@@ -148,6 +149,16 @@ static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
         return idle_time;
 }
 
+static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wall)
+{
+        u64 iowait_time = get_cpu_iowait_time_us(cpu, wall);
+
+        if (iowait_time == -1ULL)
+                return 0;
+
+        return iowait_time;
+}
+
 /*
  * Find right freq to be set now with powersave_bias on.
  * Returns the freq_hi to be used right now and will set freq_hi_jiffies,
@@ -470,14 +481,15 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
 
         for_each_cpu(j, policy->cpus) {
                 struct cpu_dbs_info_s *j_dbs_info;
-                cputime64_t cur_wall_time, cur_idle_time;
-                unsigned int idle_time, wall_time;
+                cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time;
+                unsigned int idle_time, wall_time, iowait_time;
                 unsigned int load, load_freq;
                 int freq_avg;
 
                 j_dbs_info = &per_cpu(od_cpu_dbs_info, j);
 
                 cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
+                cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time);
 
                 wall_time = (unsigned int) cputime64_sub(cur_wall_time,
                                 j_dbs_info->prev_cpu_wall);
@@ -487,6 +499,10 @@ 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;
 
+                iowait_time = (unsigned int) cputime64_sub(cur_iowait_time,
+                                j_dbs_info->prev_cpu_iowait);
+                j_dbs_info->prev_cpu_iowait = cur_iowait_time;
+
                 if (dbs_tuners_ins.ignore_nice) {
                         cputime64_t cur_nice;
                         unsigned long cur_nice_jiffies;
@@ -504,6 +520,16 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
                         idle_time += jiffies_to_usecs(cur_nice_jiffies);
                 }
 
+                /*
+                 * For the purpose of ondemand, waiting for disk IO is an
+                 * indication that you're performance critical, and not that
+                 * the system is actually idle. So subtract the iowait time
+                 * from the cpu idle time.
+                 */
+
+                if (idle_time >= iowait_time)
+                        idle_time -= iowait_time;
+
                 if (unlikely(!wall_time || wall_time < idle_time))
                         continue;