3eb23fd73c
With modification in scheduler, governor now gets predicted instantaneous demand waiting to run in addition to demand from previous window for each CPU. Make use of this information since prediction from scheduler could be more accurate than just looking at past few windows. Governor calculates two frequencies during each sampling period: one based on demand in previous sampling period (f_prev), and the other based on prediction provided by scheduler (f_pred). Max of both will be selected as final frequency. Hispeed related logic, including both frequency selection and delay is ignored when prediction is enabled. If only f_pred but not f_prev picked policy->max, max_freq_hysteresis period is not started/extended. This is to reduce power cost of mis-prediction if it happens. One use case prediction could dramatically help is when a heavy task wakes up after sleeping for a long time. With prediction, governor could ramp up to frequency the task needs much faster than before. To enable prediction, echo 1 to enable_prediction file in cpufreq interactive sysfs directory. Change-Id: I27396785886e43ea01c9000c651c8bd142172273 Suggested-by: Saravana Kannan <skannan@codeaurora.org> Signed-off-by: Junjie Wu <junjiew@codeaurora.org> |
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| .. | ||
| amd-powernow.txt | ||
| boost.txt | ||
| core.txt | ||
| cpu-drivers.txt | ||
| cpufreq-nforce2.txt | ||
| cpufreq-stats.txt | ||
| governors.txt | ||
| index.txt | ||
| intel-pstate.txt | ||
| pcc-cpufreq.txt | ||
| user-guide.txt | ||