cpu-copy-data

what does it mean when CPU copies data?

tags: learning database linux

content

• this is the process:
  • application calls read()
  • kernel takes over and initiates a disk I/O request
  • disk controller reads data from disk, copies the data to its buffer
  • without DMA, cpu reads a chunk from disk buffer, loads the data onto its registers
  • then CPU stores the chunk of data to memory

what’s the exact action that CPU is doing when it’s “copying” data?

• CPU is executing load and store instructions
• it loads data from somewhere (disk buffer or memory) to its registers
• it then stores data to another memory address

Note

so this kind of disk I/O is CPU intensive

up

• 理解下 IO 操作

down

reference