On Wed, Oct 08, 2014 at 01:54:58PM +0100, Dietmar Eggemann wrote: > > But this should be very hard. Intel Architecture has limitation to capture > > all > > the freq changes in software and also the intel_pstate should have no > > notification. > > We encountered this missing notification for current frequency with > Intel systems (e.g. i5-3320M) using the intel_pstate driver while > testing this patch-set. The arch_scale_set_curr_freq call in > __cpufreq_notify_transition [[PATCH 2/7] cpufreq: Architecture specific > callback for frequency changes] will not work on such a system. > > In our internal testing, we placed arch_scale_set_curr_freq(cpu->cpu, > sample->freq) into intel_pstate_timer_func [intel_pstate.c] to get the > current frequency for a cpu. > > The arch_scale_set_max_freq call in cpufreq_set_policy > [drivers/cpufreq/cpufreq.c] still works although the driver exposes the > max turbo pstate and not the max pstate. That's an additional problem > because we don't want to use turbo states for frequency scaling.
Right, so when we pull the policy part into the scheduler, intel_pstate will revert to just another driver without such logic and things should just work. But yes, currently it also implements policy, that needs to go away. -- 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/
