Am 23.08.21 um 13:28 schrieb Tvrtko Ursulin:
From: Tvrtko Ursulin tvrtko.ursulin@intel.com
Proposal to standardise the fdinfo text format as optionally output by DRM drivers.
Idea is that a simple but, well defined, spec will enable generic userspace tools to be written while at the same time avoiding a more heavy handed approach of adding a mid-layer to DRM.
i915 implements a subset of the spec, everything apart from the memory stats currently, and a matching intel_gpu_top tool exists.
Open is to see if AMD can migrate to using the proposed GPU utilisation key-value pairs, or if they are not workable to see whether to go vendor specific, or if a standardised alternative can be found which is workable for both drivers.
Same for the memory utilisation key-value pairs proposal.
v2:
- Update for removal of name and pid.
v3:
- 'Drm-driver' tag will be obtained from struct drm_driver.name. (Daniel)
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@intel.com Cc: David M Nieto David.Nieto@amd.com Cc: Christian König christian.koenig@amd.com Cc: Daniel Vetter daniel@ffwll.ch Cc: Daniel Stone daniel@fooishbar.org
I'm not an expert on that stuff, but as far as I can see this totally makes sense to me.
Feel free to add an Acked-by: Christian König christian.koenig@amd.com to those three patches.
Regards, Christian.
Documentation/gpu/drm-usage-stats.rst | 97 +++++++++++++++++++++++++++ Documentation/gpu/index.rst | 1 + 2 files changed, 98 insertions(+) create mode 100644 Documentation/gpu/drm-usage-stats.rst
diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst new file mode 100644 index 000000000000..c669026be244 --- /dev/null +++ b/Documentation/gpu/drm-usage-stats.rst @@ -0,0 +1,97 @@ +.. _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-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. diff --git a/Documentation/gpu/index.rst b/Documentation/gpu/index.rst index b9c1214d8f23..b99dede9a5b1 100644 --- a/Documentation/gpu/index.rst +++ b/Documentation/gpu/index.rst @@ -10,6 +10,7 @@ Linux GPU Driver Developer's Guide drm-kms drm-kms-helpers drm-uapi
- drm-usage-stats driver-uapi drm-client drivers