On Tue, 18 Jun 2013 14:10:28 +0530, Viresh Kumar wrote: > On 18 June 2013 13:54, Lukasz Majewski <l.majewski@xxxxxxxxxxx> wrote: > > On Tue, 18 Jun 2013 08:42:13 +0200, Viresh Kumar wrote: > > >> Its not about how long.. One cpu type can work longer with boost > >> freq compared to other. > >> > >> What we probably need is: > >> - Enabled boost from sysfs if required (now below steps will come > >> into picture) > >> - See how many cpus are running, if only one then start using boost > >> freqs > > > > You are right here. > > > > I'd like to propose following solution: > > 1. For acpi (where boost_enable come into play) - do not consider > > number of active cpus (this is done in HW anyway) > > > > 2. For SW solution evaluate how many CPUs are running. If only one > > is running then allow enabling boost from sysfs. > > Looks fine. Ok, > > > But following situation is also possible: User enable boost when one > > core is only running and then for some reason other core is woken > > up. What shall be done then? > > Shall we then disable boost immediately when cpufreq detects that > > more than one core is running? Or leave this situation to be > > handled by thermal subsystem? > > Obviously disable boost ASAP. Every SoC might not have a thermal > framework glue to do it. Implementation of counting number of idle CPUs would impose extending the cpufreq core itself. Do you have any hints how this can be done in a neat way? I suspect, that porting the LAB solution to the cpufreq core may be not easy. I think that the best place for it would be governor core code. > > > As a side note: > > Logic proposed at point 2, is already implemented at LAB > > (enable LAB only when one core is running and disable it when more > > than one come into play). > > Hmm.. So, eventually that will go away now :) But this is not the only functionality, which LAB posses :-). > > >> - Now thermal should be come into picture to save chip in case a > >> single cpu running at boost can burn it out. > > > > I will extent v4 to embrace code which switches off boost at > > thermal. > > Gud. Ok. -- Best regards, Lukasz Majewski Samsung R&D Institute Poland (SRPOL) | Linux Platform Group -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
