Re: [RFC][PATCH 3/9] perf: export registerred pmus via sysfs

[Lin Ming <ming.m.lin@intel.com>]

On Mon, 2010-05-10 at 17:40 +0800, Peter Zijlstra wrote:
> On Mon, 2010-05-10 at 17:27 +0800, Lin Ming wrote:
> > Export pmus via sysfs /sys/devices/system/cpu/pmus/0...N
> > The file name is the pmu id, ie, /sys/devices/system/cpu/pmus/N
> > represents pmu id N.
> > So perf tool can use it to initialize perf_event_attr. 
> 
> Why create a whole new directory, why not:
> 
>  /sys/devices/system/cpu/cpuN/pmu_id ?


Do you mean /sys/devices/system/cpu/cpuN/pmu_id contain all ids?

For example, each cpu has 4 pmus and the file pmu_id shows something
like,

#cat /sys/devices/system/cpu/cpu0/pmu_id
0 1 2 3

....

#cat /sys/devices/system/cpu/cpuN/pmu_id
0 1 2 3

> 
> That way we can simply extend it to things like:
> 
>  /sys/devices/system/cpu/cpuN/nodeN/pmu_id
>  /sys/devices/system/node/nodeN/pmi_id
> 
> Instead of having to add something like:
> 
>  /sys/devices/system/node/pmus/0..N
> 
>