aclmdlExecute

Applicability

Product

Supported

Atlas A3 training products / Atlas A3 inference products

Atlas A2 training products / Atlas A2 inference products

Atlas 200I/500 A2 inference products

Atlas inference products

Atlas training products

Description

Executes model inference until the result is returned.

The operations of loading, executing, and unloading a model must be performed in the same context. For details about how to create a context, see or .

Prototype

aclError aclmdlExecute(uint32_t modelId, const aclmdlDataset *input, aclmdlDataset *output)

Parameters

Parameter

Input/Output

Description

modelId

Input

Inference model ID.

After a model loading API (such as aclmdlLoadFromFile and aclmdlLoadFromMem) is successfully called, a model ID is returned. The ID is used as the input of this API.

input

Input

Pointer to the input data for model inference.

output

Output

Pointer to the output data for model inference.

When calling aclCreateDataBuffer to create the aclDataBuffer type for storing output data of the corresponding index, you can pass nullptr to the data parameter and set size to 0 to create an empty aclDataBuffer type. During model execution, the system automatically calculates and allocates the index output buffer. This method saves memory. However, you need to free the memory and reset the aclDataBuffer after using the data. In addition, memory copy is involved when the system allocates memory, which may cause performance loss.

The sample code for freeing the memory and resetting the aclDataBuffer is as follows:
1
2
3
4
aclDataBuffer *dataBuffer = aclmdlGetDatasetBuffer(output, 0); // Obtain the corresponding data buffer based on the index.
void *data = aclGetDataBufferAddr(dataBuffer);  // Obtain the device pointer to data.
aclrtFree(data ); // Free the device memory.
aclUpdateDataBuffer(dataBuffer, nullptr, 0); // Reset the content in the data buffer for next inference.

Returns

0 on success; else, failure. For details, see aclError.

Restrictions

  • If the same modelId is shared by multiple threads due to service requirements, locks must be added between user threads to ensure that operations of refreshing the input and output memories and executing inference are performed continuously. For example:
    // API call sequence of thread A:
    lock(handle1) -> aclrtMemcpy refreshes the input and output memory -> aclmdlExecute runs inference -> unlock(handle1)
    
    // API call sequence of thread B:
    lock(handle1) -> aclrtMemcpy refreshes the input and output memory -> aclmdlExecute runs inference -> unlock(handle1)
  • The memory for storing model input and output data is the device memory. You can call APIs such as and to allocate device memory.
    • For details about the scenarios and restrictions of each memory allocation API, see the API description in Memory Management.
    • The hi_mpi_dvpp_malloc API is a dedicated memory allocation API for media data processing. To reduce copy, the output of media data processing is used as the input of model inference to implement memory reuse.
    • Hardware has memory alignment and supplement requirements. If you use one of these APIs to allocate a large memory block, and divide and manage the memory, the alignment and supplement restrictions of the corresponding API must be met. For details, see Secondary Memory Allocation.

See Also

For details about the API call sequence and sample code, see Running a Model.