I noticed all the stock governors except for hotplug do not turn off the second core. I would use ondemand and interactive and notice that the second core never goes offline, the only time it does is if I use hotplug. I thought by now the new kernel would allow hotplugging using the other governors but apparently not. Battery life is better using hotplug. I know that even though the second core is on it's not doing anything and it could be argued that using two cores to finish a job faster will bring both cores back to idle faster, but the slight improvement in battery using hotplug seems to go against that. Anyone else notice this?