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authorStratos Karafotis <stratosk@semaphore.gr>2013-02-28 17:57:32 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-04-01 01:11:35 +0200
commit9366d84052e7c5b2eca804c08cfcd00b490f4de2 (patch)
tree0f159a425d29f1c6be12dbf30f18a55b79ae72d2 /drivers/cpufreq/cpufreq_ondemand.c
parentcpufreq: conservative: Fix relation when decreasing frequency (diff)
downloadlinux-9366d84052e7c5b2eca804c08cfcd00b490f4de2.tar.xz
linux-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.c11
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];