mmu

How does kernel know, which pages in the virtual address space correspond to a swapped out physical page frame?

by

Linux: When swap file is used the Page Table Entry gets updated with one marked as invalid and holding information about where it is saved in the swap file. That is: an index to the swap_info array and an offset within the swap_map. Example from (an a bit old) Page Table Entry type (pte_t) on … Read more

Difference between logical addresses, and physical addresses?

by

This answer is by no means exhaustive but it may explain it enough to make things click. In virtual memory systems, there is a disconnect between logical and physical addresses. An application can be given a virtual address space of (let’s say) 4G. This is its usable memory and it’s free to use it as … Read more

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)