Physical memory management
by Justus Winter for GNU Project
The GNU Mach kernel maps all physical memory into the kernel address space, and uses virtual memory to provide continuous chunks for kernel objects like IPC tables. This imposes a limit of ~250000 ports. It is the most pressing scalability issue. We propose to replace the page allocator by a buddy allocator to provide continuous chunks of memory directly from the physical memory, to use it as a backend for the slab allocator, and to replace the IPC tables by a more scalable data structure.