The algorithm sparsely uses 512MB of virtual address space for its allocation and caches. For each of about 40 sizes, it keeps an array of fixed size blocks, pl

The algorithm sparsely uses 512MB of virtual address space for its allocation and caches. For each of about 40 sizes, it keeps an array of fixed size blocks, plus a bunch of per thread and per CPU caches. In a 32bit world, taking 1/4 to 1/8 of the address space would be impolite. In a 64 (or 48) bit world it doesn't matter.