memfs swap space

A new memfs mount option global_swapmax allows administrators to specify a global memory pool to be shared by all mounted memfs file systems, thereby:

• reducing the total amount of memory needed for all memfs file systems

• providing more available space to individual memfs file systems than if they each allocated their own memory space using the swapmax option

See mount_memfs(1M).

During initial system installation, shared space for /tmp and /var/tmp file systems is allocated by default, and total swap space (/dev/swap) is autotuned based on available disk space, memfs space, and total memory size.