[Intel-gfx] [RFC i-g-t] intel-gpu-top: Rewrite the tool to be safe to use

[Chris Wilson]

Quoting Tvrtko Ursulin (2018-03-28 19:29:48)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> intel-gpu-top is a dangerous tool which can hang machines due unsafe mmio
> register access. This patch rewrites it to use only PMU.
> 
> Only overall command streamer busyness and GPU global data such as power
> and frequencies are included in this new version.
> 
> For access to more GPU functional unit level data, an OA metric based tool
> like gpu-top should be used instead.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
> Cc: Petri Latvala <petri.latvala at intel.com>

Looked good to me.

Someone might complain about the loss of "stats" mode, but we can point
them towards "perf record" now.

Half-reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris