kernel hang when reboot with loaded ip_vs_rr.ko

[Sam Wan]

I built ip_vs_rr.ko in 7.2 Release.
There is no problem when loaded ipvs.ko.
After I loaded ip_vs_rr.ko, and reboot the system, the entire system is hang.
Here is a list of the ip_vs moudles have built:

modules # ls -l
total 118
drwxr-xr-x  2 root  wheel    512 May  8 15:20 ./
drwxr-xr-x  8 root  wheel    512 May  9 21:22 ../
-r-xr-xr-x  1 root  wheel   5366 May  8 15:20 ip_vs_dh.ko*
-r-xr-xr-x  1 root  wheel   8249 May  8 15:20 ip_vs_lblc.ko*
-r-xr-xr-x  1 root  wheel   9783 May  8 15:20 ip_vs_lblcr.ko*
-r-xr-xr-x  1 root  wheel   4560 May  8 15:20 ip_vs_lc.ko*
-r-xr-xr-x  1 root  wheel   4592 May  8 15:20 ip_vs_nq.ko*
-r-xr-xr-x  1 root  wheel   4838 May  8 15:20 ip_vs_rr.ko*
-r-xr-xr-x  1 root  wheel   4574 May  8 15:20 ip_vs_sed.ko*
-r-xr-xr-x  1 root  wheel   5366 May  8 15:20 ip_vs_sh.ko*
-r-xr-xr-x  1 root  wheel   4574 May  8 15:20 ip_vs_wlc.ko*
-r-xr-xr-x  1 root  wheel   5634 May  8 15:20 ip_vs_wrr.ko*
-r-xr-xr-x  1 root  wheel  43081 May  8 15:20 ipvs.ko*
-rw-r--r--  1 root  wheel    360 May  8 15:20 linker.hints

What is the problem?
Important is how to get more information about this kernel module is  hang?

Your suggestion is highly appreciated.

Thanks