All the active (non-idle) cores in a package will run at same frequency. But, cores enter various C-states (idle state) depending on how long they are going to be idle, etc. This is managed by cpuidle. Each core can be in different C-state. And the remaining active cores can go to higher frequency using Turbo mode. Thanks, Venki On Mon, 2009-03-16 at 13:28 -0700, michael k lang wrote: > Take a look at the slides (around 29): > http://www.cs.utexas.edu/users/cart/arch/beeman.ppt > > Should be able to control individual cores freqs/Cstates. (Unless I'm > reading them wrong.) > > But if this is handled by the ACPI drivers maybe I'm looking in the > wrong space. > Thanks, > --Mike > > On Fri, 2009-03-13 at 04:51 +0000, Matthew Garrett wrote: > > On Thu, Mar 12, 2009 at 11:44:56AM -0600, michael k lang wrote: > > > > > I would like to be able to put a single core to the C6 state. Also to > > > set individual frequency of cores in a socket. > > > > C states are handled by the ACPI processor driver, not the cpufreq > > driver. They're a function of the idle loop in the kernel - a CPU in a C > > state other than C0 can't execute code. To the best of my knowledge, > > it's not possible to set the frequency of individual cores in a package. > > The primary reason to alter frequency is to be able to drop the core > > voltage, and Intel's architecture fixes the voltage per package. > > Dropping the frequency of an individual core rather than the entire > > package wouldn't save power. > > > > -- > 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 -- 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
