clGetEventProfilingInfo

Returns profiling information for the command associated with event if profiling is enabled.

`cl_int clGetEventProfilingInfo (`	cl_event `event`,
	cl_profiling_info `param_name`,
	size_t `param_value_size`,
	void `*param_value`,
	size_t `*param_value_size_ret)`

Parameters

event

Specifies the event object.

param_name

Specifies the profiling data to query. The list of supported param_name types and the information returned in param_value by clGetEventProfilingInfo is described in the table of parameter queries below.

param_value_size

Specifies the size in bytes of memory pointed to by param_value. This size must be greater than or equal to the size of return type as described in the table bolow.

param_value

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

param_value_size_ret

Returns the actual size in bytes of data copied to param_value. If param_value_size_ret is NULL, it is ignored.

The following is a table of clGetEventProfilingInfo parameter queries

cl_profiling_info	Return Type	Info. returned in `param_value`
`CL_PROFILING_COMMAND_QUEUED`	cl_ulong	A 64-bit value that describes the current device time counter in nanoseconds when the command identified by `event` is enqueued in a command-queue by the host.
`CL_PROFILING_COMMAND_SUBMIT`	cl_ulong	A 64-bit value that describes the current device time counter in nanoseconds when the command identified by `event` that has been enqueued is submitted by the host to the device associated with the command-queue.
`CL_PROFILING_COMMAND_START`	cl_ulong	A 64-bit value that describes the current device time counter in nanoseconds when the command identified by `event` starts execution on the device.
`CL_PROFILING_COMMAND_END`	cl_ulong	A 64-bit value that describes the current device time counter in nanoseconds when the command identified by `event` has finished execution on the device.

Notes

The unsigned 64-bit values returned can be used to measure the time in nano-seconds consumed by OpenCL commands.

OpenCL devices are required to correctly track time across changes in device frequency and power states. The CL_DEVICE_PROFILING_TIMER_RESOLUTION specifies the resolution of the timer i.e. the number of nanoseconds elapsed before the timer is incremented.

Event objects can be used to capture profiling information that measure execution time of a command. Profiling of OpenCL commands can be enabled either by using a command-queue created with CL_QUEUE_PROFILING_ENABLE flag set in properties argument to clCreateCommandQueue.

Errors

Returns CL_SUCCESS if the function is executed successfully and the profiling information has been recorded. Otherwise, it returns one of the following errors:

CL_PROFILING_INFO_NOT_AVAILABLE if the CL_QUEUE_PROFILING_ENABLE flag is not set for the command-queue, if the execution status of the command identified by event is not CL_COMPLETE or if event is a user event object.
CL_INVALID_VALUE if param_name is not valid, or if size in bytes specified by param_value_size is less than the size of return type as described in the above table and param_value is not NULL.
CL_INVALID_EVENT if event is a not a valid event 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.

Specification

OpenCL Specification

Also see

clCreateCommandQueue, clSetCommandQueueProperty

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