[Intel-gfx] [RFC 3/6] drm/i915: Expose list of clients in sysfs

[Chris Wilson]

Quoting Tvrtko Ursulin (2019-05-10 14:22:37)
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> Expose a list of clients with open file handles in sysfs.
> 
> This will be a basis for a top-like utility showing per-client and per-
> engine GPU load.
> 
> Currently we only expose each client's pid and name under opaque numbered
> directories in /sys/class/drm/card0/clients/.
> 
> For instance:
> 
> /sys/class/drm/card0/clients/3/name: Xorg
> /sys/class/drm/card0/clients/3/pid: 5664

Random thought, should this be a symlink to /proc/$pid or a pidfd?
-Chris