On 2 June 2013 01:07, Rafael J. Wysocki <rjw@xxxxxxx> wrote: > On Saturday, June 01, 2013 08:26:47 PM Viresh Kumar wrote: >> Even removal of __cpufreq_driver_getavg() should be done in a separate >> patch, so that it can be reverted easily if required later. > > Why would you want to revert it separately? We might not need to revert all the changes that Stratos is doing. Only a revert of getavg() and its users + a small fix in governor would be enough. Stratos patch isn't only about removing getavg() but how ondemand works and so breaking stuff might be more useful. >> >> "Proportional to load" means C * load, so why is "policy->max / 100" *the* right C? >> > >> > I think, finally(?) I see your point. The right C should be "policy->cpuinfo.max_freq / 100". >> >> Why are you changing it to cpuinfo.max_freq?? This is fixed once a driver is >> initialized.. but user may request a lower max freq for a governor or policy. >> Which is actually reflected in policy->max I believe. > > Which doesn't matter. The formula should provide the same results regardless > of the user settings except that the selected frequency should be capped by > policy->max (instead of being proportional to it). I think using > cpuinfo.max_freq here is correct. I am confused now about what to use.. This is how I read it: Assumption: CPU supports following freq range.. 500 MHz, 600 MHz, 700 MHz, 800 MHz, 900 MHz, 1 GHz cpuinfo.max_freq = 1 GHz policy->max is set to 600 MHz Case 1: Use policy->max: We need load to be over 500/600 (i.e. .834) to move to 600 MHz. Case 2: Use cpuinfo.max_freq.. We need load to be over 500/1000 (i.e. .5) to move to 600 MHz. So, obviously the calculations aren't the same.. Now, this is how I understood these two different variables: - cpuinfo.max_freq: >> Over that why keeping following check is useful anymore? >> >> if (load_freq > od_tuners->up_threshold) >> goto max. >> >> As, if load is over 95, then even policy->max * 95 / 100 will even give almost >> the same freq. > > Yes, in the majority of cases. > > Thanks, > Rafael > > > -- > I speak only for myself. > Rafael J. Wysocki, Intel Open Source Technology Center. -- 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
