2009/310 Disk IO PM Enhancement 1999/388 2005/250 2008/465

[Edward Pilatowicz]

On Tue, May 19, 2009 at 10:37:45AM -0700, Terry Whatley wrote:
>      4.3.4 disk power attribute driver properties
>
> 	sd(7D) will export a set of driver properties to indicate a disk's
> 	power attributes. See Table-2.
>
> 	Table-1 Disk Power Attribute Properties (array properties are indexed
> 		by power state in order of ascending power levels)
> 	------------------------------------------------------------------------
> 	Prop Name            Prop Type    | Prop Description
> 	------------------------------------------------------------------------
> 	"pm-resource-type"      String    | "resource-spindle-disk" for the
>                                           | spindle disks
> 	------------------------------------------------------------------------
> 	"pm-perf" Integer array           | array of average R/W
>                                           | performance percentages
> 	------------------------------------------------------------------------
> 	"pm-pwr-saving"  Integer array    | array of average power saving in
>                                           | units of 0.1watt
> 	------------------------------------------------------------------------
> 	"pm-latency"     Integer array    | array of time to first data in units
>                                           | of 100ms
> 	------------------------------------------------------------------------
>

exporting performance statistics via device properties seems weird to
me.  is there a precedent for this?  why isn't this information being
exported via kstats?  do we really want to train users to start using
prtconf -v to get performance data?

ed