What is waitfortargetfps? Anyones know?

I have a mobile game, recently game fps has down 30fps, but I don’t know why this, so I applied profiler to my game then “waitfortargetfps” function take 70~80% of cpu usage.

I don’t know waitfortargetfps, who can explain it? and how can I delete that?

It is the wait time of CPU to get response from GPU because of its calculations. We can say that waitfortargetfps is the free time of CPU because it is waiting for GPU to complete its calculations.