02.11.2019 01:23, Dmitry Osipenko пишет: > 02.11.2019 00:58, Michał Mirosław пишет: >> On Wed, Oct 30, 2019 at 01:00:17AM +0300, Dmitry Osipenko wrote: >>> The ACTMON governor is interrupt-driven and currently hardware's polling >>> interval is fixed to 16ms in the driver. Devfreq supports variable polling >>> interval by the generic governors, let's re-use the generic interface for >>> changing of the polling interval. Now the polling interval can be changed >>> dynamically via /sys/class/devfreq/devfreq0/polling_interval. >> [...] >>> @@ -308,7 +308,7 @@ static unsigned long actmon_device_target_freq(struct tegra_devfreq *tegra, >>> unsigned int avg_sustain_coef; >>> unsigned long target_freq; >>> >>> - target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD; >>> + target_freq = dev->avg_count / tegra->devfreq->profile->polling_ms; >>> avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold; >>> target_freq = do_percent(target_freq, avg_sustain_coef); >>> target_freq += dev->boost_freq; >> >> Noting a comment in patch 13, if this is hot path you could try reciprocal_divide(). > > Hello Michał, > > This not really a hot path, I just wanted to optimize that case to keep > things a bit nicer. > > Please take a look at the arch/arm/boot/compressed/lib1funcs.S, firstly > it checks whether divisor is a power of 2 value and then takes optimized > code path that uses a single shift. Hence the patch 13 still applies here. On the other hand, there is now only a single case of the division by polling_ms in the driver which won't bring much benefit, so it indeed makes sense to skip the patch 13 for now.
