Virtual memory is conceptually simple but potentially devastating to performance. Every memory access must go through segmentation (add segment base, check limit) and then paging (look up the page table). Naively, paging alone requires two additional memory reads per access -- one for the page directory entry, one for the page table entry.
Servers in 105 countries
，这一点在新收录的资料中也有详细论述
# Staged changes only
Трехстороннюю встречу по Украине отложили20:29