[Intel-gfx] [PATCH 2/5] drm/i915: Expose list of clients in sysfs

[Tvrtko Ursulin]

On 16/12/2019 12:51, Chris Wilson wrote:
> Quoting Tvrtko Ursulin (2019-12-16 12:07:01)
>> 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
>>
>> v2:
>>   Chris Wilson:
>>   * Enclose new members into dedicated structs.
>>   * Protect against failed sysfs registration.
>>
>> v3:
>>   * sysfs_attr_init.
>>
>> v4:
>>   * Fix for internal clients.
>>
>> v5:
>>   * Use cyclic ida for client id. (Chris)
> 
> I think we are now in the age of xa_alloc_cyclic(). At least the
> immediate benefit is that we don't have to worry about the ida locking.

Also spin locks and GFP_KERNEL in the current patch do not mix well. Use 
with caution until I send the updated version out.

Regards,

Tvrtko