Extracting data from cudnnBackendDescriptor_t

C++
1

Hello!
I’m recently studying about cudnn. To be more specific, I’m trying to extract data from (cudnnBackendDescriptor_t variantPack and cudnnBackendDescriptor_t executionPlan). However, I extracted doubtful data from it. Below is my code and result.

The code
void printVariantPackPointers(cudnnBackendDescriptor_t variantPack, cudnnBackendDescriptor_t executionPlan) {
void* ptrValue = nullptr;
int64_t count1 = 0;
int64_t count2 = 0;
int64_t requested_count = 10;
int64_t workspaceSize = 32;

cudnnStatus_t status = cudnnBackendGetAttribute(
    executionPlan,
    CUDNN_ATTR_EXECUTION_PLAN_WORKSPACE_SIZE,
    CUDNN_TYPE_INT64,
    1,
    &count1,
    &workspaceSize
);
if (status == CUDNN_STATUS_SUCCESS) {
    std::cout << "Workspace Size: " << workspaceSize << " bytes" << std::endl;
} else {
    std::cout << "Failed to get workspace size: " << cudnnGetErrorString(status) << std::endl;
}

status = cudnnBackendGetAttribute(
    variantPack,
    CUDNN_ATTR_VARIANT_PACK_DATA_POINTERS,
    CUDNN_TYPE_VOID_PTR,
    requested_count,
    &count2,
    ptrValue
);
if (status == CUDNN_STATUS_SUCCESS) {
    std::cout << "Attribute (VOID_PTR): " << ptrValue << std::endl;
} else {
    std::cout << "Failed to get attribute: " << cudnnGetErrorString(status) << std::endl;
}

}

The result
Workspace Size: 0 bytes
Failed to get attribute: CUDNN_STATUS_NOT_SUPPORTED

I’m pretty sure that the execution plan is from pytorch cudnn run_conv_plan function. Is there any chance that conv plan actually does not have any workspace?
I’m also curious that why CUDNN_STATUS_NOT_SUPPORTED error happens. I will appreciate if someone help me here

Thank you in advance!