2022-04-01 22:22:03 +08:00
|
|
|
.. _drm-client-usage-stats:
|
|
|
|
|
|
|
|
|
|
======================
|
|
|
|
|
DRM client usage stats
|
|
|
|
|
======================
|
|
|
|
|
|
|
|
|
|
DRM drivers can choose to export partly standardised text output via the
|
|
|
|
|
`fops->show_fdinfo()` as part of the driver specific file operations registered
|
|
|
|
|
in the `struct drm_driver` object registered with the DRM core.
|
|
|
|
|
|
|
|
|
|
One purpose of this output is to enable writing as generic as practicaly
|
|
|
|
|
feasible `top(1)` like userspace monitoring tools.
|
|
|
|
|
|
|
|
|
|
Given the differences between various DRM drivers the specification of the
|
|
|
|
|
output is split between common and driver specific parts. Having said that,
|
|
|
|
|
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.
|
|
|
|
|
- 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.
|
|
|
|
|
|
|
|
|
|
Mandatory fully standardised keys
|
|
|
|
|
---------------------------------
|
|
|
|
|
|
|
|
|
|
- drm-driver: <str>
|
|
|
|
|
|
|
|
|
|
String shall contain the name this driver registered as via the respective
|
|
|
|
|
`struct drm_driver` data structure.
|
|
|
|
|
|
|
|
|
|
Optional fully standardised keys
|
|
|
|
|
--------------------------------
|
|
|
|
|
|
|
|
|
|
- drm-pdev: <aaaa:bb.cc.d>
|
|
|
|
|
|
|
|
|
|
For PCI devices this should contain the PCI slot address of the device in
|
|
|
|
|
question.
|
|
|
|
|
|
|
|
|
|
- drm-client-id: <uint>
|
|
|
|
|
|
|
|
|
|
Unique value relating to the open DRM file descriptor used to distinguish
|
|
|
|
|
duplicated and shared file descriptors. Conceptually the value should map 1:1
|
|
|
|
|
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.
|
|
|
|
|
|
|
|
|
|
- drm-engine-<str>: <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
|
|
|
|
|
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>
|
|
|
|
|
|
|
|
|
|
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
|
|
|
|
|
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-memory-<str>: <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
|
|
|
|
|
string here.
|
|
|
|
|
|
|
|
|
|
Value shall reflect the amount of storage currently consumed by the buffer
|
|
|
|
|
object belong to this client, in the respective memory region.
|
|
|
|
|
|
|
|
|
|
Default unit shall be bytes with optional unit specifiers of 'KiB' or 'MiB'
|
|
|
|
|
indicating kibi- or mebi-bytes.
|
2022-04-01 22:22:05 +08:00
|
|
|
|
2022-06-10 01:42:12 +08:00
|
|
|
- drm-cycles-<str> <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
|
|
|
|
|
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]
|
|
|
|
|
|
|
|
|
|
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
|
|
|
|
|
time active without considering what frequency the engine is operating as a
|
|
|
|
|
percentage of it's maximum frequency.
|
|
|
|
|
|
2022-04-01 22:22:05 +08:00
|
|
|
===============================
|
|
|
|
|
Driver specific implementations
|
|
|
|
|
===============================
|
|
|
|
|
|
|
|
|
|
:ref:`i915-usage-stats`
|
