my observations with clFlush and clFinish


I am running opencv test suite with opencl enabled on odroid-XU having POWERVRSGX544 MP3 GPU, i have seen that clFlush and clFinish taking more time to complete its work, blocking the cpu. And one more thing i have observed is all the commands are being issued only after clFlush or clFininsh functions are encountered and one more observation with clFlush is that, the control is returning from clFLush only after all the tasks executing is completed, till then the cpu is being blocked, so i have commented clFlush and clFinish to see that whether the GPU will execute the commands in the queue or not if it does not reach clFlush or ClFinish, but it is issuing all the commands present in command queue, unable to understand the behaviour.Can anyone guide me?