Kernel execution time

In my program the execution time of the kernel is more than the execution time of the entire program

In the output screen (Attached Screenshot) 'Execution time of kernel' is measured using 'clGetEventProfilingInfo'

and 'Execution time' is measured using clock_t, similar to this link and it measures the total time taken by the main function

This issue occurs only when I run my code on DevCloud, if I run it on my PC then Execution time > Kernel Execution time

Why is this happening?

int main()
{
        .
        .
        .
	start = clock();
        .
        .
	err = clEnqueueNDRangeKernel(queue, multiply_ker, 1, NULL, &global, &local, 0, NULL, &event);
	clWaitForEvents(1, &event);
	clFinish(queue);
        .
        .
        .

	end = clock();

}