Project: buddy system allocator

• Author: zhichao-yan
• Class: CS452/CS552 [Operating Systems]

Overview

This is allocator with buddy memory allocation algorithm.

Manifest

• buddy.c: source file
• buddy.h: head file
• buddy-unit-test.c: for unit test
• buddy-test.c: for test in order to compare with malloc/free allocator as blow
• malloc-test.c: malloc/free test

Building the project

1. make
2. export LD_LIBRARY_PATH = .
3. ./buddy-test 100 1234 sor ./buddy-unit-test s

Testing

1. buddy unit test(Malloc and free 1 byte) ./buddy-unit-test v
2. Stability test: run successfully without crashing ./buddy-test 20000000 1234 s
3. Performance: better than malloc/free allocator

root@iZbp19rh4d6jcag5epp4hrZ:~/buddy-system# time ./buddy-test 20000000 1234 s

real    0m1.149s
user    0m1.147s
sys     0m0.000s
root@iZbp19rh4d6jcag5epp4hrZ:~/buddy-system# time ./malloc-test 20000000 1234 s  

real    0m1.782s
user    0m1.780s
sys     0m0.000s

Known Bugs

bug all fixed.

1. need to notice the conditions when the buddy is mergeable.buddy must be free and in the same block size

2. sbrk() function cannot give you an aligned address,in this case,you cannot use below way to find corresponding buddy,you need to do alignment by yourself or use other functions e.g. int posix_memalign(void **memptr, size_t alignment, size_t size);

your_buddy_address = your_address^(1ULL<<your_kval));

cites

1. github