Tagged: #virtual-memory

The kernel's own malloc — a hierarchy of zone allocators, the kalloc heap, and slab caches for specific types. Different from user-side VM, and just as important.

How XNU responds when memory gets tight — the four-stage pressure pipeline from free pages through compression to swap to process termination, and what each stage costs.

Walk a single mmap call from libc, through BSD into Mach VM, the lazy first-touch fault, and the pmap entry that finally makes the file accessible as memory.

The dyld shared cache pre-links every system dylib into one file mapped into every process. Where it lives, how shared regions work, and why it saves RAM.

How macOS virtual memory works inside XNU: vm_map address spaces, pmap page tables, page faults, the memory compressor, and jetsam under pressure.