Messages in this thread | | | Date | Tue, 16 Jul 2013 12:04:22 -0700 | From | Greg KH <> | Subject | Re: driver model, duplicate names question |
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A: No. Q: Should I include quotations after my reply?
http://daringfireball.net/2007/07/on_top
On Tue, Jul 16, 2013 at 11:54:31AM -0700, Srinivas Pandruvada wrote: > Hi, > > I am assigned to do add a powercap class. There are several > technologies, which will allow to add a power budget to an individual > device. For example, you can set a power budget to a individual > physical cpu package, each core and uncore devices, GPUs, DRAM etc.
"classes" all reference a "device" in the system, I don't see that in your tree below, where does that come in? How do I, as someone who created a device in the system know to create a your new powercap class for it?
In other words, are you _sure_ you want a class here and not something else (i.e. a bus?)
> +The Power Capping framework organizes power capping devices under a tree structure. > +At the root level, each device is under some "controller", which is the enabler > +of technology. For example this can be "RAPL". > +Under each controllers, there are multiple power zones, which can be independently > +monitored and controlled. > +Each power zone can be organized as a tree with parent, children and siblings. > +Each power zone defines attributes to enable power monitoring and constraints.
Ah, this sounds like you want to be a bus, as you have a controller, and then devices attached to it.
> +Example Sys-FS Interface > + > +/sys/class/power_cap/intel-rapl > +├── package-0 > +│ ├── constraint-0 > +│ │ ├── name > +│ │ ├── power_limit_uw > +│ │ └── time_window_us > +│ ├── constraint-1 > +│ │ ├── name > +│ │ ├── power_limit_uw > +│ │ └── time_window_us > +│ ├── core > +│ │ ├── constraint-0 > +│ │ │ ├── name > +│ │ │ ├── power_limit_uw > +│ │ │ └── time_window_us > +│ │ ├── energy_uj > +│ │ └── max_energy_range_uj > +│ ├── dram > +│ │ ├── constraint-0 > +│ │ │ ├── name > +│ │ │ ├── power_limit_uw > +│ │ │ └── time_window_us > +│ │ ├── energy_uj > +│ │ └── max_energy_range_uj > +│ ├── energy_uj > +│ ├── max_energy_range_uj > +│ └── max_power_range_uw > +├── package-1 > +│ ├── constraint-0 > +│ │ ├── name > +│ │ ├── power_limit_uw > +│ │ └── time_window_us > +│ ├── constraint-1 > +│ │ ├── name > +│ │ ├── power_limit_uw > +│ │ └── time_window_us > +│ ├── core > +│ │ ├── constraint-0 > +│ │ │ ├── name > +│ │ │ ├── power_limit_uw > +│ │ │ └── time_window_us > +│ │ ├── energy_uj > +│ │ └── max_energy_range_uj > +│ ├── dram > +│ │ ├── constraint-0 > +│ │ │ ├── name > +│ │ │ ├── power_limit_uw > +│ │ │ └── time_window_us > +│ │ ├── energy_uj > +│ │ └── max_energy_range_uj > +│ ├── energy_uj > +│ ├── max_energy_range_uj > +│ └── max_power_range_uw > +├── power > +│ ├── async > +│ ├── autosuspend_delay_ms > +│ ├── control > +│ ├── runtime_active_kids > +│ ├── runtime_active_time > +│ ├── runtime_enabled > +│ ├── runtime_status > +│ ├── runtime_suspended_time > +│ └── runtime_usage > +├── subsystem -> ../../../../class/power_cap > +└── uevent
Ick. Rewrite this to use a bus and you should be fine, right? Don't use a class, a class is only to be used if you have a device that is a specific "type of thing". Like a tty device, it is a class, as lots of different "real" devices can have tty ports on them (usb, pci, pcmcia, platform, etc.)
Rethink this using a bus and see if that solves your issues. You get a hierarchy with that. And you can have different "types" of devices on your bus, making it easy to tell the difference between a "package" and a "constraint".
Does that help?
greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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