C Specification

To return information about a kernel object, call the function

cl_int clGetKernelInfo(
    cl_kernel kernel,
    cl_kernel_info param_name,
    size_t param_value_size,
    void* param_value,
    size_t* param_value_size_ret);


  • kernel specifies the kernel object being queried.

  • param_name specifies the information to query. The list of supported param_name types and the information returned in param_value by clGetKernelInfo is described in the Kernel Object Queries table.

  • param_value is a pointer to memory where the appropriate result being queried is returned. If param_value is NULL, it is ignored.

  • param_value_size is used to specify the size in bytes of memory pointed to by param_value. This size must be ≥ size of return type as described in the Kernel Object Queries table.

  • param_value_size_ret returns the actual size in bytes of data being queried by param_name. If param_value_size_ret is NULL, it is ignored.


Table 1. List of supported param_names by clGetKernelInfo
Kernel Info Return Type Description



Return the kernel function name.



Return the number of arguments to kernel.



Return the kernel reference count.



Return the context associated with kernel.



Return the program object associated with kernel.


missing before version 1.2.


Returns any attributes specified using the __attribute__ OpenCL C qualifier (or using an OpenCL C++ qualifier syntax [[]] ) with the kernel function declaration in the program source. These attributes include attributes described in the earlier OpenCL C kernel language specifications and other attributes supported by an implementation.

Attributes are returned as they were declared inside __attribute__((...)), with any surrounding whitespace and embedded newlines removed. When multiple attributes are present, they are returned as a single, space delimited string.

For kernels not created from OpenCL C source and the clCreateProgramWithSource API call the string returned from this query will be empty.

clGetKernelInfo returns CL_SUCCESS if the function is executed successfully. Otherwise, it returns one of the following errors:

  • CL_INVALID_VALUE if param_name is not valid, or if size in bytes specified by param_value_size is < size of return type as described in the Kernel Object Queries table and param_value is not NULL.

  • CL_INVALID_KERNEL if kernel is a not a valid kernel object.

  • CL_OUT_OF_RESOURCES if there is a failure to allocate resources required by the OpenCL implementation on the device.

  • CL_OUT_OF_HOST_MEMORY if there is a failure to allocate resources required by the OpenCL implementation on the host.

See Also

Document Notes

For more information, see the OpenCL Specification

This page is extracted from the OpenCL Specification. Fixes and changes should be made to the Specification, not directly.

Copyright 2014-2023 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0

1. The reference count returned should be considered immediately stale. It is unsuitable for general use in applications. This feature is provided for identifying memory leaks.