CPU time increasing as kernel time increases


I’ve read several times that the kernel calls are asynchronous, however, profiling (with all the counters off, so the kernels should keep executing asynchronously) my application reveals that the CPU time for the kernel call is increasing as the kernel GPU time increases. Is this normal behavior of an asynchronous call or is something wrong like a flag or something that makes the kernel call synchronous?

P.D. (Sorry for the english, not my native language)

Thanks in advance :D