Lock all pages currently mapped into the processs address space.
Lock all pages mapped into the processs address space in the future, at the time the mapping is established. Note that this may cause future mappings to fail if those mappings cause resource limits to be exceeded.
Since physical memory is a potentially scarce resource, processes are limited in how much they can lock down. A single process can lock the minimum of a system-wide "wired pages" limit and the per-process RLIMIT_MEMLOCK resource limit.
The munlockall call unlocks any locked memory regions in the process address space. Any regions mapped after an munlockall call will not be locked.