Re: [RFC] [PATCH 1/1] perf: add support for arch-dependent symbolic event names to "perf stat"

[Corey Ashford <cjashfor@linux.vnet.ibm.com>]

On 3/11/2010 11:14 AM, Ingo Molnar wrote:
>
> * Corey Ashford<cjashfor@linux.vnet.ibm.com>  wrote:
[snip]
>> I'm not sure how that would work.  The issue I am trying to solve
>> here is that Power arch chips have a large number of very
>> hardware-specific events that are not generalizable.  Many of these
>> events not only have names, but other user-configurable bits as well
>> that select or narrow the scope of which exact events are recorded.
>> This issue is dealt with nicely in libpfm4, as it has mechanisms for
>> parsing event names and attributes (aka modifiers or unit masks),
>> and then produces a usable config field for the perf_events_attr
>> struct.
>>
>> Should I take it from the above that you are completely against the
>> idea of using an external library for hardware-specific event and
>> attribute naming?
>
> Could you give a few relevant examples of events in question, and the kind of
> configurability/attributes they have on Power?

Here are a few examples for the Power A2 processor.  I've distorted the names 
because PMU architecture isn't publicly released yet.

PM_DE_PMC_9:hrd_mask=0xff:hrd=0x22:pma_mask=0x3fff:pma=0x1b2d:culling_mode=3
PM_EX_0x03:lane=2:vlane=1
PM_OWE_ENG_MAC_FULL:usu=3

Note that the attribute fields shown above are fitted into the config field of 
the perf_event_attr struct.

>
> Thanks,
>
> 	Ingo

Regards,

- Corey