[Panda] Debug mem alloc
Merge branch 'master' of github.com:stpddream/OSHomework

Conflicts:
	hw4/mem_taichi/mem.c
	hw4/mem_taichi/mem_record.h
	hw4/mem_taichi/mem_taichi
	hw4/mem_taichi/util.c
	hw4/mem_taichi/util.h