Nvprof shows kernels with strange grid size and block size [0,0,0]

Hi all,
I profiled my program, and then I notice there are many children kernels with strange size [0,0,0] taking a lot of time(please reference the first image, attached file: block000.png).
These kernels have strange grid size and block size (0,0,0)(the second image). I have confirmed I never issue these kernel with printf, and the tab “GPU details”(the third image) doesn’t show these strange kernels. Dose anyone can explain the situation?



block000.png
all_normal_children_kernel.png
timeline.png