tmpfs added to NetBSD (Updated)
Julio M. Merino Vidal has committed the work on the
"tmpfs" Summer-of-Code project
into NetBSD. The long-term goal is to use tmpfs to replace
the existing MFS, which
``is an implementation of the on-disk FFS file-system over memory
pages. It is not "memory-friendly" because it arranges data as if it
was using a disk. Furthermore, it never releases memory pages,
which makes it unusable in several scenarios. OTOH, tmpfs uses
data structures that can easily exist in memory and works closely with
UVM to handle many things transparently (basically, regular files).''
In other words: mfs can only grow but never shrink and free up the
memory it ocupies, while tmpfs will free memory again when files
For all information on how to enable tmpfs, run a regression test
and where to find documentation about the internals of tmpfs see
Julio's posting to tech-kern.
Update: See also
for information on the import and the latest changes!
[Tags: google-soc, tmpfs]