COPY-ON-WRITE: copy content to new space rather than directly overwriting

(Only happen when memory’s reference count >=2, otherwise it is safe to 

overwrite).

Zero space: all fields are zero, not necessarily to allocate actual space.

OOM – out of memory

Page replacement strategies:

-FIFO

-LRU

-Clock Algo (after class reading, similar to distributed consistent hashing)

Next Project:

Implement:

-malloc

-free

malloc is desired to be Lock-free as well as thread-safe

Some introductions of sys calls (refer to man page for details):

- brk  (grow the heap size)

- sbrk (shrink the heap size)

- strace [options: -p <pid>/ -o/ -c] (program’s sys calls’ lookup)

- ltrace

How to manage the VM space? (allocate, free, collected, reuse)

-- linked list

Implement: metadata above each allocated block (the next list node, current node’s 

size etc)

-- Buddy system: have different linked list for different size memory blocks

malloc of large blocks: use mmap

Benchmarks: malloc efficiency will be evaluated, do optimization if it is possible.