Re: [PATCH 1/3]cpuidle take2: Core cpuidle infrastructure

[Dave Jones <davej@redhat.com>]

On Thu, Feb 22, 2007 at 01:52:57PM -0800, Venkatesh Pallipadi wrote:

 > Announcing 'cpuidle', a new CPU power management infrastructure to manage
 > idle CPUs in a clean and efficient manner.
 > cpuidle separates out the drivers that can provide support for multiple types
 > of idle states and policy governors that decide on what idle state to use
 > at run time.
 > A cpuidle driver can support multiple idle states based on parameters like
 > varying power consumption, wakeup latency, etc (ACPI C-states for example).
 > A cpuidle governor can be usage model specific (laptop, server,
 > laptop on battery etc).
 > Main advantage of the infrastructure being, it allows independent development
 > of drivers and governors and allows for better CPU power management.

I played with this a little, and got puzzled.
My quad core box used exactly the same amount of power whether the
'ladder' governer was loaded & in use or not.  In both situations
it was exactly the same as a vanilla 2.6.20

I'd have expected it to use more until I loaded up 'ladder' to bring it
on par featurewise with 2.6.20.  What did I miss?

		Dave

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