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| author | Stratos Karafotis <stratosk@semaphore.gr> | 2013-02-28 16:57:32 +0000 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2013-04-01 01:11:35 +0200 |
| commit | 9366d84052e7c5b2eca804c08cfcd00b490f4de2 (patch) | |
| tree | 0f159a425d29f1c6be12dbf30f18a55b79ae72d2 /drivers/cpufreq/cpufreq_ondemand.c | |
| parent | fed573d5c91ab8f12801740cfac0567e33635b1e (diff) | |
| download | lwn-9366d84052e7c5b2eca804c08cfcd00b490f4de2.tar.gz lwn-9366d84052e7c5b2eca804c08cfcd00b490f4de2.zip | |
cpufreq: governors: Calculate iowait time only when necessary
Currently we always calculate the CPU iowait time and add it to idle time.
If we are in ondemand and we use io_is_busy, we re-calculate iowait time
and we subtract it from idle time.
With this patch iowait time is calculated only when necessary avoiding
the double call to get_cpu_iowait_time_us. We use a parameter in
function get_cpu_idle_time to distinguish when the iowait time will be
added to idle time or not, without the need of keeping the prev_io_wait.
Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Acked-by: Viresh Kumar <viresh.kumar@linaro.,org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq/cpufreq_ondemand.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq_ondemand.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index 459f9ee39c74..14714787b724 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -339,11 +339,20 @@ static ssize_t store_io_is_busy(struct dbs_data *dbs_data, const char *buf, struct od_dbs_tuners *od_tuners = dbs_data->tuners; unsigned int input; int ret; + unsigned int j; ret = sscanf(buf, "%u", &input); if (ret != 1) return -EINVAL; od_tuners->io_is_busy = !!input; + + /* we need to re-evaluate prev_cpu_idle */ + for_each_online_cpu(j) { + struct od_cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, + j); + dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j, + &dbs_info->cdbs.prev_cpu_wall, od_tuners->io_is_busy); + } return count; } @@ -414,7 +423,7 @@ static ssize_t store_ignore_nice(struct dbs_data *dbs_data, const char *buf, struct od_cpu_dbs_info_s *dbs_info; dbs_info = &per_cpu(od_cpu_dbs_info, j); dbs_info->cdbs.prev_cpu_idle = get_cpu_idle_time(j, - &dbs_info->cdbs.prev_cpu_wall); + &dbs_info->cdbs.prev_cpu_wall, od_tuners->io_is_busy); if (od_tuners->ignore_nice) dbs_info->cdbs.prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE]; |