On 06/07/2018 08:57, Vincent Guittot wrote: > Update entry/exit latency and residency time of hikey960 to use more > realistic figures based on unitary tests done on the platform. > > The complete results (in us) : > big cluster > cluster CPU > max entry latency 800 400 > max exit latency 2900 550 > residency 903Mhz 5000 1500 > residency 2363Mhz 0 1500 > > little cluster > cluster CPU > max entry latency 500 400 > max exit latency 1600 650 > residency 533Mhz 8000 4500 > residency 1844Mhz 0 1500 > > We can see that the residency time depends of the running OPP which is not > handled for now. Then we also have to take into account the constraint of > a residency time shorter than the tick to get full advantage of idle loop > reordering(tick is stopped if idle duration is higher than tick period). > Finally the selected residency value are : > big cluster > cluster CPU > residency 3700 1500 > > little cluster > cluster CPU > residency 3500 1500 > > A simple test with a task waking up every 11,111ms shows improvement: > - 5% a lowest OPP > - 22% at highest OPP > > The period has been chosen: > - to be shorter than old cluster residency time and longer than new > residency time od cluster off C-state > - to prevent any sync with tick (4ms) when running tests that can add > some variances between tests > > Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx> > --- Great! Thanks for fixing the values. Acked-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx> -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
