mindspore.runtime.set_cpu_affinity

mindspore.runtime.set_cpu_affinity(enable_affinity, affinity_cpu_list=None)

Enable thread-level core binding to assign specific CPU cores to MindSpore's main modules (main thread, pynative, runtime, minddata), to prevent unstable performance caused by MindSpore's threads seizing CPU.

Note

• Provides two binding modes: 1. Automatically generates binding policies based on available CPUs, NUMA nodes, and device resources in the environment to bind cores at thread level. 2. Thread-level bonding based on customized bonding policies passed in by affinity_cpu_list.

• The automated bind-core policy generation scenario invokes system commands to obtain CPU, NUMA node, and device resources on the environment, and some commands cannot be executed successfully due to environment differences; the automated bind-core policy generated will vary according to the resources available on the environment:

  1. cat /sys/fs/cgroup/cpuset/cpuset.cpus, to obtain the available CPU resources on the environment; if the execution of this command fails, the bind-core function will not take effect.

  2. npu-smi info -m, get the available NPU resources on the environment; if the execution of this command fails, the bind-core policy will be generated only based on the available CPU resources, without considering the device affinity.

  3. npu-smi info -t board -i {NPU_ID} -c {CHIP_ID}, get NPU details based on the logical ID of the device; if the execution of this command fails, the bind-core policy is generated based on the available CPU resources only, regardless of device affinity.

  4. lspci -s {PCIe_No} -vvv, get the hardware information of the device on the environment; if the execution of this command fails, the bind-core policy is generated only based on the available CPU resources, without considering the device affinity.

  5. lscpu, get information about CPUs and NUMA nodes on the environment; if the execution of this command fails, only the available CPU resources are used to generate the bind-core policy, without considering the device affinity.

Parameters

• enable_affinity (bool) – Switches on/off thread-level core binding.

• affinity_cpu_list (dict, optional) – Specifies a customized bind-core policy. The key to be passed into the dict needs to be in string "deviceX" format, and the value needs to be in list ["cpuidX-cpuidY"] format. Default: None, i.e., use the bind-core policy generated automatically based on the environment. It is allowed to pass the empty dict {}, in which case the bind-core policy generated automatically based on the environment will be used.

Raises

• TypeError – The parameter enable_affinity is not a boolean.

• TypeError – The parameter affinity_cpu_list is neither a dictionary nor a None.

• ValueError – The key of parameter affinity_cpu_list is not a string.

• ValueError – The key of parameter affinity_cpu_list is not in "deviceX" format.

• ValueError – The parameter affinity_cpu_list has a value that is not a list.

• ValueError – The element in value of parameter affinity_cpu_list is not a string.

• ValueError – The element in value for parameter affinity_cpu_list does not match ["cpuidX-cpuidY"].

• RuntimeError – Automatically generated binding policy or customized binding policy scenario where the number of CPU cores assigned to each device is less than 7.

• RuntimeError – A custom-specified binding policy scenario where the CPU assigned to a device is not available in the environment.

• RuntimeError – The mindspore.runtime.set_cpu_affinity API is called repeatedly.

Examples

>>> import mindspore as ms
>>> ms.set_device("Ascend", 1)
>>> ms.runtime.set_cpu_affinity(True)
>>>
>>> import mindspore as ms
>>> ms.set_device("Ascend", 1)
>>> ms.runtime.set_cpu_affinity(True, {"device0":["0-9"],"device1":["10-15","20-29"],"device2":["35-45"]})