@WKPlus

The Linux kernel supports the following overcommit handling modes

0 - Heuristic overcommit handling. Obvious overcommits of
address space are refused. Used for a typical system. It
ensures a seriously wild allocation fails while allowing
overcommit to reduce swap usage. root is allowed to
allocate slightly more memory in this mode. This is the
default.

1 - Always overcommit. Appropriate for some scientific
applications. Classic example is code using sparse arrays
and just relying on the virtual memory consisting almost
entirely of zero pages.

2 - Don't overcommit. The total address space commit
for the system is not permitted to exceed swap + a
configurable amount (default is 50%) of physical RAM.
Depending on the amount you use, in most situations
this means a process will not be killed while accessing
pages but will receive errors on memory allocation as
appropriate.

Useful for applications that want to guarantee their
memory allocations will be available in the future
without having to initialize every page.