March 30, 2015
5:16 p.m.
On Mon, 30 Mar 2015 20:25:38 +0530, Sunny Shah said:
- The book says, about releasing page frames to the per CPU cache - "no page frame is ever released to the cold cache: the kernel always assumes the freed page frame is hot with respect to the hardware cache". What is the reason for this decision ?
What can go wrong if the page is cold but the kernel assumes it's hot? What can go wrong if the kernel assumes it's cold but it's actually hot? (Hint - in which cases will it do a cache flush? In which cases is a cache flush needed? What happens in each case if the kernel guesses wrong?)