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;