Vincent, On Mon, Feb 7, 2011 at 3:55 PM, Vincent Guittot <vincent.guit...@linaro.org> wrote: > Hi vishwa, > > I have passed cpufreq-bench on my platform. The results below have > been reached with a sampling rate of 20ms and a sampling_down factor > set to 10. > > I have a question about the sampling_down feature : The ondemand delay > value is calculated before calling dbs_check_cpu, but dbs_check_cpu > can modify rate_mult. This implies that if the rate_mult is set to 1 > in dbs_check_cpu because we set something else than the max frequency, > the next sampling period will be sampling_rate*sampling_down_factor > (the one used for max freq) but the frequency can be the lowest one. > We should rather calculate the delay after dbs_check_cpu or i miss > something ? Good point. Yes, with current implementation, change in rate_mult will have effect only after next do_dbs_timer is called and the point raised by you is perfectly valid. Why don't you post this query to cpu_freq mailing list?
Vishwa > > Vincent > > Test results with current implementation, 20ms sampling rate, > sampling_down = 10: > _round 1: 59.14% > _round 2: 56.87% > _round 3: 77.31% > _round 4: 88.44% > _round 5: 89.56% > _round 6: 83.17% > _round 7: 89.87% > _round 8: 94.33% > _round 9: 92.98% > _round 10: 91.12% > > Test results when the delay is calculated after dbs_check_cpu, 20ms > sampling rate, sampling_down = 10 : > _round 1: 86.75% > _round 2: 91.18% > _round 3: 93.23% > _round 4: 96.70% > _round 5: 95.87% > _round 6: 96.04% > _round 7: 97.39% > _round 8: 97.37% > _round 9: 98.88% > _round 10: 97.78% > _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
