On Thu, 2009-10-08 at 15:20 +0530, Arun R Bharadwaj wrote:

* Arun R Bharadwaj [off-list ref] [2009-10-08 15:18:28]:

Implement a list based registering mechanism for architectures which
have multiple sets of idle routines which are to be registered.

Currently, in x86 it is done by merely setting pm_idle = idle_routine
and managing this pm_idle pointer is messy.

To give an example of how this mechanism works:
In x86, initially, idle routine is selected from the set of poll/mwait/
c1e/default idle loops. So the selected idle loop is registered in cpuidle
as one idle state cpuidle devices. Once ACPI comes up, it registers
another set of idle states on top of this state. Again, suppose a module
registers another set of idle loops, it is added to this list.

This provides a clean way of registering and unregistering idle state
routines.

So cpuidle didn't already have a list of idle functions it takes an
appropriate one from?

Then what does this governor do?

Also, does this imply the governor doesn't consider these idle routines?