2021.8.2

https://www.kernel.org/doc/gorman/html/understand/index.html

chap 8

RAM

  • Kernal code, kernel data structure
  • Dynamic memory

Physical memory management

  • contiguous memory
    • Page Frame Management
    • Memory Area Management
  • non-contiguous memory
    • Noncontinuous Memory Area Management

memory zone

  • DMA: <16MB
  • NORMAL: 16MB-896MB 内核数据，虚存3GB-4GB
  • HIGHMEM: >896MB
  • hhhhh

the pool of reserved page frames

内存不够时，会保留一部分做紧急使用