Re: [rfc 3/3] perf, x86: P4 PMU -- export ABI part of event config to userspace

Cyrill Gorcunov
2010-11-24T08:48:14Z

On 11/24/10, Peter Zijlstra <peterz@infradead.org> wrote:
> On Wed, 2010-11-24 at 01:46 +0300, Cyrill Gorcunov wrote:
>> plain text document attachment (x86-perf-export-abi)
>> Due to tight 64 bit size of event config field (where we have to track
>> pretty lot of info during event lifetime) some bits are to be exported
>> via header into userspace.
>>
>> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
>> CC: Lin Ming <ming.m.lin@intel.com>
>> CC: Stephane Eranian <eranian@google.com>
>> CC: Peter Zijlstra <peterz@infradead.org>
>> ---
>>
>> Note that I don't like much the idea to export anything into userspace
>> but it seems there is no other choise. So there is a minimum which should
>> be exported.
>
>
> Could you say what exactly is exposed to userspace and why?

yes, we need two enums to be exported, because we use custom encoding,
which is described in first patch. peter i'll describe more detailed
in a couple of hours, ok?
>