Issue No.10 - October (1975 vol.24)
E. Von Puttkamer , the Department of Computer Science, Unversity of Kaiserslautern
The design of a simple hardware memory allocator is described, which allocates blocks of different lengths L = 2h = K, K-1,..., K-n in a memory according to the buddy system algorithm. The binary tree, representing the distribution of free and used blocks in memory is mapped into a set of shift registers. They are connected for end-around shifting and clocked with frequencies different for each register, preserving thereby the internal structure of the binary tree. A small counter, attached to each shift register in the set holds the address of the first free block and can be read out on request within 0.5 ?s. A simple control unit realizes the algorithm. Having answered a request the system needs about 130 ?s to compute the addresses of free blocks in a total of 511 blocks managed by the device.
Binary tree representations, buddy system reprerentations, hardware: substitution of software, operating systems: memory allocation.
E. Von Puttkamer, "A Simple Hardware Buddy System Memory Allocator", IEEE Transactions on Computers, vol.24, no. 10, pp. 953-957, October 1975, doi:10.1109/T-C.1975.224100