that revises the netmap memory allocator so that the
various parameters (number and size of buffers, rings, descriptors)
can be modified at runtime through sysctl variables.
The changes become effective when no netmap clients are active.
The API is mostly unchanged, although the NIOCUNREGIF ioctl now
does not bring the interface back to normal mode: and you
need to close the file descriptor for that.
This change was necessary to track who is using the mapped region,
and since it is a simplification of the API there was no
incentive in trying to preserve NIOCUNREGIF.
We will remove the ioctl from the kernel next time we need
a real API change (and version bump).
Among other things, buffer allocation when opening devices is
now much faster: it used to take O(N^2) time, now it is linear.
Submitted by: Giuseppe Lettieri
http://info.iet.unipi.it/~luigi/vale/
VALE lets you dynamically instantiate multiple software bridges
that talk the netmap API (and are *extremely* fast), so you can test
netmap applications without the need for high end hardware.
This is particularly useful as I am completing a netmap-aware
version of ipfw, and VALE provides an excellent testing platform.
Also, I also have netmap backends for qemu mostly ready for commit
to the port, and this too will let you interconnect virtual machines
at high speed without fiddling with bridges, tap or other slow solutions.
The API for applications is unchanged, so you can use the code
in tools/tools/netmap (which i will update soon) on the VALE ports.
This commit also syncs the code with the one in my internal repository,
so you will see some conditional code for other platforms.
The code should run mostly unmodified on stable/9 so people interested
in trying it can just copy sys/dev/netmap/ and sys/net/netmap*.h
from HEAD
VALE is joint work with my colleague Giuseppe Lettieri, and
is partly supported by the EU Projects CHANGE and OPENLAB
