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

Peter Zijlstra
2010-11-24T08:32:06Z

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?