On Thu, 24 Feb 2011, Peter Zijlstra wrote: > On Thu, 2011-02-24 at 15:24 -0500, Nicolas Pitre wrote: > > > Most SMP ARM processors are going to use it soon. Powering down idle > > cores provides substantial power saving. > > And why can't regular idle paths be used? CPU hotplug is a massively > expensive operation. To achieve the same result from idle, you need to exclude the core from any unwanted wakeup. At the moment cpu unplug is the only way to achieve that. If you want to do the same from idle, then we need the isolation features Frederic is working on for RT/HPC. They allow us to isolate cores completely for totaly different reasons, but it could be resused to provide full isolation of a core in a very deep power state. That would solve the problem w/o going through kstompmachine Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
