On Wed, Jun 18, 2014 at 10:36 AM, Lorenzo Pieralisi
[off-list ref] wrote:

On Fri, Jun 13, 2014 at 06:33:35PM +0100, Nicolas Pitre wrote:

quoted

On Fri, 13 Jun 2014, Lorenzo Pieralisi wrote:

quoted

On Wed, Jun 11, 2014 at 07:15:16PM +0100, Nicolas Pitre wrote:

quoted

...__[EXEC]__|__[PREP]--|__[ENTRY]__|__[IDLE]__|___[EXIT]_--|__[EXEC]__...
             |          |           |          |            |
             |<-- entry-latency --->|
                                               |<- exit-  ->|
                                               |  latency   |
             |<-------------- min-residency --------------->|
                        |<----- worst_wakeup_latency ------>|

entry-latency: Worst case latency required to enter the idle state.  The
exit_latency may be guaranteed only after entry-latency has passed.

min-residency: Minimum period, including preparation, entry and exit,
for a given power mode to be worthwhile energy wise.  It must be at
least equal to entry_latency + exit_latency.

Ok, a minor tweak to the diagram above, min-residency should include
energy costs related to idle entry and exit, but not the exit-latency
itself, as long as the energy costs implied by exiting the state are
factored out in the min-residency-us property.

This makes sense to me..

It includes accounting for the energy cost vs WFI of prep/entry/exit,
but timing is from the end of the previous exec, until the event is
expected to trigger.

Thanks!

Sebastian