'The relationship between kswapd、low memory killer(lmk) and low memory killer daemon(lmkd)？

In my cognition.if lmk does not exist,lmkd will kill process.otherwise,it will call lmk to kill process.I have some question about this way.

Is lmk called by utilizing a callback function when shrink_slab is called?if it's correct, then can i think that lmkd wakes up lmk by shrink_slab?
Kswapd will call shrink_slab,so can i think kswapd will call lmk?
if no lmkd, when will lmk be called? only by kswapd?
Is there a timer that periodically schedules kswapd?

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Solution	Source