freebsd-nq/sys/modules/geom/geom_zero
Pawel Jakub Dawidek 565bc10111 Add a very simple and small GEOM class - ZERO.
It creates very huge provider (41PB) /dev/gzero.
On BIO_READ request it zero-fills bio_data and on BIO_WRITE it does nothing.
You can also set kern.geom.zero.clear sysctl to 0 to do nothing even for
BIO_READ.

I'm using it for performance testing where it is very helpful.

MFC after:	3 days
2005-07-25 10:03:16 +00:00
..
Makefile