Need a help on kswapd process working
 

Please help me out with the working of kernel swap deamon working..
like how it will get called and how it will get to know the number of pages remaining are low and how it will free up the pages.. I got to know a working diagram of kswapd from a famous book of Robert love about Linux virtual Memory Manager. if someone can explain this diagram also it will be a great help.. thanks

https://www.kernel.org/doc/gorman/ht...005.html#toc12

fig 2.2 if any one can explain kswapd working.