On 23/05/14 16:52, Vincent Guittot wrote: > power_orig is only changed for system with a SMT sched_domain level in order > to > reflect the lower capacity of CPUs. Heterogenous system also have to reflect > an > original capacity that is different from the default value. > > Create a more generic function arch_scale_cpu_power that can be also used by > non SMT platform to set power_orig. > > The weak behavior of arch_scale_cpu_power is the previous SMT one in order to > keep backward compatibility in the use of power_orig. > > Signed-off-by: Vincent Guittot <vincent.guit...@linaro.org>
As you know, besides uarch scaled cpu power for HMP, freq scaled cpu power is important for energy-aware scheduling to achieve freq scale invariance for task load. I know that your patch-set is not about introducing freq scaled cpu power, but we were discussing how this can be achieved w/ your patch-set in place, so maybe you can share your opinion regarding the easiest way to achieve freq scale invariance with us? (1) We assume that the current way (update_cpu_power() calls arch_scale_freq_power() to get the avg power(freq) over the time period since the last call to arch_scale_freq_power()) is suitable for us. Do you have another opinion here? (2) Is the current layout of update_cpu_power() adequate for this, where we scale power_orig related to freq and then related to rt/(irq): power_orig = scale_cpu(SCHED_POWER_SCALE) power = scale_rt(scale_freq(power_orig)) or do we need an extra power_freq data member on the rq and do: power_orig = scale_cpu(SCHED_POWER_SCALE) power_freq = scale_freq(power_orig)) power = scale_rt(power_orig)) In other words, do we consider rt/(irq) pressure when calculating freq scale invariant task load or not? Thanks, -- Dietmar [...] -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/