This project present a unique frame allocator based on the buddy allocator. This enables the allocation of three different sizes from Intel x86-64 page tables; 4Kb, 2Mb and 1Gb. The algorithm effectively allocates and deallocates frames using 512-ary threes and two Intel-specific instructions (BSF & BSR).
Memory overhead is less than 20Mb for 512Gb.
The allocator code is located in the file allocator/allocator.rs. The main goal of the allocator is to return an address when requested for one of the following size: 4Kb, 2Mb and 1Gb. Once an memory zone is allocated, it cannot be reused until it is deallocated (no memory sharing).
Folder bsf_benchmark contains the benchmark of bit scan forward (BSF) compared to a simple loop. Bit scan forward operator returns the index of the first 1, it is used to effeciently find the first free page.
Folder distribution contains external fragmentation measurement given a predifined scenario which simulate a memory usage of 70%.