| Date | Mon, 21 Jan 2013 12:53:57 -0800 | From | Greg Kroah-Hartman <> | Subject | Re: [RFC][Update 2][PATCH 2/4] ACPI / PM: Expose reference count values of ACPI power resources |
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On Mon, Jan 21, 2013 at 02:05:47PM +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Since ACPI power resources are going to be used more extensively on > new hardware platforms, it becomes necessary for user space (powertop > in particular) to observe some properties of those resources for > diagnostics purposes. > > For this reason, export the reference counts of ACPI power resources > to user space by adding a new reference_count attribute to the sysfs > directory representing each power resource. The value read from > that attribute represents the number of devices using the power > resource at the given time. If that value is 0, it meas that the > power resource is not used and therefore it has been turned off.
Why does userspace need to know a reference count? Is it so that if it is not 0, it can work to try to lower it to 0? Or something else?
thanks,
greg k-h
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