@@ -17,41 +17,42 @@ wherever possible effort should still be made to standardise as much as
possible.
File format specification
=========================
- File shall contain one key value pair per one line of text.
- Colon character (`:`) must be used to delimit keys and values.
- All keys shall be prefixed with `drm-`.
- Whitespace between the delimiter and first non-whitespace character shall be
ignored when parsing.
-- Neither keys or values are allowed to contain whitespace characters.
+- Keys are not allowed to contain whitespace characters.
- Numerical key value pairs can end with optional unit string.
- Data type of the value is fixed as defined in the specification.
Key types
---------
1. Mandatory, fully standardised.
2. Optional, fully standardised.
3. Driver specific.
Data types
----------
- <uint> - Unsigned integer without defining the maximum value.
-- <str> - String excluding any above defined reserved characters or whitespace.
+- <keystr> - String excluding any above defined reserved characters or whitespace.
+- <valstr> - String.
Mandatory fully standardised keys
---------------------------------
-- drm-driver: <str>
+- drm-driver: <valstr>
String shall contain the name this driver registered as via the respective
`struct drm_driver` data structure.
Optional fully standardised keys
--------------------------------
Identification
^^^^^^^^^^^^^^
@@ -68,62 +69,62 @@ to the in kernel representation of `struct drm_file` instances.
Uniqueness of the value shall be either globally unique, or unique within the
scope of each device, in which case `drm-pdev` shall be present as well.
Userspace should make sure to not double account any usage statistics by using
the above described criteria in order to associate data to individual clients.
Utilization
^^^^^^^^^^^
-- drm-engine-<str>: <uint> ns
+- drm-engine-<keystr>: <uint> ns
GPUs usually contain multiple execution engines. Each shall be given a stable
-and unique name (str), with possible values documented in the driver specific
+and unique name (keystr), with possible values documented in the driver specific
documentation.
Value shall be in specified time units which the respective GPU engine spent
busy executing workloads belonging to this client.
Values are not required to be constantly monotonic if it makes the driver
implementation easier, but are required to catch up with the previously reported
larger value within a reasonable period. Upon observing a value lower than what
was previously read, userspace is expected to stay with that larger previous
value until a monotonic update is seen.
-- drm-engine-capacity-<str>: <uint>
+- drm-engine-capacity-<keystr>: <uint>
Engine identifier string must be the same as the one specified in the
-drm-engine-<str> tag and shall contain a greater than zero number in case the
+drm-engine-<keystr> tag and shall contain a greater than zero number in case the
exported engine corresponds to a group of identical hardware engines.
In the absence of this tag parser shall assume capacity of one. Zero capacity
is not allowed.
-- drm-cycles-<str>: <uint>
+- drm-cycles-<keystr>: <uint>
Engine identifier string must be the same as the one specified in the
-drm-engine-<str> tag and shall contain the number of busy cycles for the given
+drm-engine-<keystr> tag and shall contain the number of busy cycles for the given
engine.
Values are not required to be constantly monotonic if it makes the driver
implementation easier, but are required to catch up with the previously reported
larger value within a reasonable period. Upon observing a value lower than what
was previously read, userspace is expected to stay with that larger previous
value until a monotonic update is seen.
-- drm-maxfreq-<str>: <uint> [Hz|MHz|KHz]
+- drm-maxfreq-<keystr>: <uint> [Hz|MHz|KHz]
Engine identifier string must be the same as the one specified in the
-drm-engine-<str> tag and shall contain the maximum frequency for the given
-engine. Taken together with drm-cycles-<str>, this can be used to calculate
-percentage utilization of the engine, whereas drm-engine-<str> only reflects
+drm-engine-<keystr> tag and shall contain the maximum frequency for the given
+engine. Taken together with drm-cycles-<keystr>, this can be used to calculate
+percentage utilization of the engine, whereas drm-engine-<keystr> only reflects
time active without considering what frequency the engine is operating as a
percentage of it's maximum frequency.
Memory
^^^^^^
- drm-memory-<region>: <uint> [KiB|MiB]
Each possible memory type which can be used to store buffer objects by the
GPU in question shall be given a stable and unique name to be returned as the