What does process kworker/dying mean

I am trying to find out why my system freezes often. I started process accounting using accton and when I view the results using sa I see this line:
376 3.90% 3516.77re 68.71% 0.00u 0.00% 0.22s 24.32% 0avio 0k kworker/dying*

So kworker/dying is using up a lot of my cpu. I understand that kworker represents a process doing kernal work, but what does it mean when appended with /dying ?