[虛擬化; VM; VMM ;Vmemory #補Container](https://alvislu01.notion.site/VM-VMM-Vmemory-Container-69d28042a3e04420acd9e2534fe40e04)

Virtual Memory

Copy on Write ( COW ) # 用於 Fork system call

優缺點

VM軟體

技術:Demand Paging = Paging + lazy swapper / Valid Invalid Bit

Page Fault

EMAT求算

降低 Page Fault Ratio 方法 👇🏼EMAT中的P

1️⃣Page Replacement Algo選擇

Page Replacement Algo ⭐

Belady Anomaly ⚠️

2️⃣ Frame 數目分配多寡 ( 硬體決定 )

3️⃣Page Size ⭐⭐⭐

4️⃣Program Structure : array; loop


Thrashing⚠️及防範方法:Page Fault Frequency & Working set mode