Re: [RFC][PATCH] perf: sysfs type id

[Greg KH <gregkh@suse.de>]

On Wed, Nov 10, 2010 at 10:36:51AM +1100, Michael Ellerman wrote:
> On Tue, 2010-11-09 at 14:13 -0800, Greg KH wrote:
> > On Tue, Nov 09, 2010 at 10:45:19PM +0100, Peter Zijlstra wrote:
> > > The below is a RFC patch adding dynamic type ids to perf.
> > > 
> > > We need to represent PMUs in sysfs because we want to allow multiple
> > > (loadable) PMUs and need a way to identify them.
> > > 
> > > This patch creates a new device class "pmu" and adds a single attribute
> > > "type" to it. This device attribute will expose the dynamic type id as
> > > required by perf_event_attr::type.
> > > 
> > > The sysfs layout looks like:
> > > 
> > > [root@westmere ~]# cd /sys/class/pmu/
> > 
> > You missed the embedded track at Plumbers where we talked about never
> > adding another class to the kernel.  Please use bus_id instead for this.
> 
> At least in the examples I've seen creating a bus requires a lot more
> code than a class. Or is there a shortcut I don't know about when it's a
> virtual bus?
> 
> (Interested because I have code that is using a class)

It shouldn't be that much more code to do so.  Have a pointer to some
code that you want converted over so I can show you exactly what is
needed?

thanks,

greg k-h