VM Strict Overcommit -------------------- Robert Love Design and original implementation by Alan Cox These patches are a port of his work to various other kernels (2.4 and 2.5) and VM (rmap and not). What is Strict Overcommit? -------------------------- Introduce new overcommit policies that attempt to never succeed an allocation that can not be fulfilled by the backing store and consequently never OOM. This is achieved through strict accounting of the committed address space and a policy to allow/refuse allocations based on that accounting. Currently we have 5 overcommit modes: no overcommit handling, heuristic overcommit handling (default), swapless strict overcommit, standard strict overcommit, and paranoid but perfect strict overcommit. These are implemented as a sysctl and /proc entry. See Documentation/vm/overcommit-accounting and mm/mmap.c::vm_enough_memory() for more information.