Labels

GPU labels originate from two main sources: NFD rules and GPU plugin (& NFD hook).

NFD rules

NFD rule is a method to instruct NFD to add certain label(s) to node based on the devices detected on it. There is a generic rule to identify all Intel GPUs. It will add labels for each PCI device type. For example, a Tigerlake iGPU (PCI Id 0x9a49) will show up as:

gpu.intel.com/device-id.0300-9a49.count=1
gpu.intel.com/device-id.0300-9a49.present=true

For data center GPUs, there are more specific rules which will create additional labels for GPU family, product and device count. For example, Flex 170:

gpu.intel.com/device.count=1
gpu.intel.com/family=Flex_Series
gpu.intel.com/product=Flex_170

For MAX 1550:

gpu.intel.com/device.count=2
gpu.intel.com/family=Max_Series
gpu.intel.com/product=Max_1550

Current covered platforms/devices are: Flex 140, Flex 170, Max 1100 and Max 1550.

To identify other GPUs, see the graphics processor table here.

GPU Plugin and NFD hook

In GPU plugin, these labels are only applied when Resource Management is enabled. With the NFD hook, labels are created regardless of how GPU plugin is configured.

Numeric labels are converted into extended resources for the node (with NFD) and other labels are used directly by GPU Aware Scheduling (GAS). Extended resources should only be used with GAS as Kubernetes scheduler doesn’t properly handle resource allocations with multiple GPUs.

Default labels

Following labels are created by default.

name	type	description
`gpu.intel.com/millicores`	number	node GPU count * 1000.
`gpu.intel.com/memory.max`	number	sum of detected GPU memory amounts in bytes OR environment variable value * GPU count
`gpu.intel.com/cards`	string	list of card names separated by '`.`'. The names match host `card*`-folders under `/sys/class/drm/`. Deprecated, use `gpu-numbers`.
`gpu.intel.com/gpu-numbers`	string	list of numbers separated by '`.`'. The numbers correspond to device file numbers for the primary nodes of given GPUs in kernel DRI subsystem, listed as `/dev/dri/card<num>` in devfs, and `/sys/class/drm/card<num>` in sysfs.
`gpu.intel.com/tiles`	number	sum of all detected GPU tiles in the system.
`gpu.intel.com/numa-gpu-map`	string	list of numa node to gpu mappings.

If the value of the gpu-numbers label would not fit into the 63 character length limit, you will also get labels gpu-numbers2, gpu-numbers3… until all the gpu numbers have been labeled.

The tile count gpu.intel.com/tiles describes the total amount of tiles on the system. System is expected to be homogeneous, and thus the number of tiles per GPU can be calculated by dividing the tile count with GPU count.

The numa-gpu-map label is a list of numa to gpu mapping items separated by _. Each list item has a numa node id combined with a list of gpu indices. e.g. 0-1.2.3 would mean: numa node 0 has gpus 1, 2 and 3. More complex example would be: 0-0.1_1-3.4 where numa node 0 would have gpus 0 and 1, and numa node 1 would have gpus 3 and 4. As with gpu-numbers, this label will be extended to multiple labels if the length of the value exceeds the max label length.

PCI-groups (optional)

GPUs which share the same PCI paths under /sys/devices/pci* can be grouped into a label. GPU nums are separated by ‘.’ and groups are separated by ‘_’. The label is created only if environment variable named GPU_PCI_GROUPING_LEVEL has a value greater than zero. GPUs are considered to belong to the same group, if as many identical folder names are found for the GPUs, as is the value of the environment variable. Counting starts from the folder name which starts with pci.

For example, the SG1 card has 4 GPUs, which end up sharing pci-folder names under /sys/devices. With a GPU_PCI_GROUPING_LEVEL of 3, a node with two such SG1 cards could produce a pci-groups label with a value of 0.1.2.3_4.5.6.7.

name	type	description
`gpu.intel.com/pci-groups`	string	list of pci-groups separated by '`_`'. GPU numbers in the groups are separated by '`.`'. The numbers correspond to device file numbers for the primary nodes of given GPUs in kernel DRI subsystem, listed as `/dev/dri/card<num>` in devfs, and `/sys/class/drm/card<num>` in sysfs.

If the value of the pci-groups label would not fit into the 63 character length limit, you will also get labels pci-groups2, pci-groups3… until all the PCI groups have been labeled.

Limitations

For the above to work as intended, GPUs on the same node must be identical in their capabilities.

GPU memory

GPU memory amount is read from sysfs gt/gt* files and turned into a label. There are two supported environment variables named GPU_MEMORY_OVERRIDE and GPU_MEMORY_RESERVED. Both are supposed to hold numeric byte amounts. For systems with older kernel drivers or GPUs which do not support reading the GPU memory amount, the GPU_MEMORY_OVERRIDE environment variable value is turned into a GPU memory amount label instead of a read value. GPU_MEMORY_RESERVED value will be scoped out from the GPU memory amount found from sysfs.