When launching a kernel, there’s a way to specify the dimension of a grid, but is there a way to specify the number of grids to launch? The Programming Guide has diagrams with labels like “Grid 0, Grid 1, etc.” but how are the number of grids determined?
There is only ever a single grid, because there is only ever a single active kernel. Those diagrams in Chapter 2 showing more than one grid are doing so in the context of a sequence of running kernels.