ADMtek AL981 "Comet" chipset. The AL981 is yet another DEC tulip clone,
except with simpler receive filter options. The AL981 has a built-in
transceiver, power management support, wake on LAN and flow control.
This chip performs extremely well; it's on par with the ASIX chipset
in terms of speed, which is pretty good (it can do 11.5MB/sec with TCP
easily).
I would have committed this driver sooner, except I ran into one problem
with the AL981 that required a workaround. When the chip is transmitting
at full speed, it will sometimes wedge if you queue a series of packets
that wrap from the end of the transmit descriptor list back to the
beginning. I can't explain why this happens, and none of the other tulip
clones behave this way. The workaround this is to just watch for the end
of the transmit ring and make sure that al_start() breaks out of its
packet queuing loop and waiting until the current batch of transmissions
completes before wrapping back to the start of the ring. Fortunately, this
does not significantly impact transmit performance.
This is one of those things that takes weeks of analysis just to come
up with two or three lines of code changes.
adapter (and some workalikes). Also add man pages and a wicontrol
utility to manipulate some of the card parameters.
This driver was written using information gleaned from the Lucent HCF Light
library, though it does not use any of the HCF Light code itself, mainly
because it's contaminated by the GPL (but also because it's pretty gross).
The HCF Light lacks certain featurs from the full (but proprietary) HCF
library, including 802.11 frame encapsulation support, however it has
just enough register information about the Hermes chip to allow someone
with enough spare time and energy to implement a proper driver. (I would
have prefered getting my hands on the Hermes manual, but that's proprietary
too. For those who are wondering, the Linux driver uses the proprietary
HCF library, but it's provided in object code form only.)
Note that I do not have access to a WavePOINT access point, so I have
only been able to test ad-hoc mode. The wicontrol utility can turn on
BSS mode, but I don't know for certain that the NIC will associate with
an access point correctly. Testers are encouraged to send their results
to me so that I can find out if I screwed up or not.
This is a seriously beefed up chroot kind of thing. The process
is jailed along the same lines as a chroot does it, but with
additional tough restrictions imposed on what the superuser can do.
For all I know, it is safe to hand over the root bit inside a
prison to the customer living in that prison, this is what
it was developed for in fact: "real virtual servers".
Each prison has an ip number associated with it, which all IP
communications will be coerced to use and each prison has its own
hostname.
Needless to say, you need more RAM this way, but the advantage is
that each customer can run their own particular version of apache
and not stomp on the toes of their neighbors.
It generally does what one would expect, but setting up a jail
still takes a little knowledge.
A few notes:
I have no scripts for setting up a jail, don't ask me for them.
The IP number should be an alias on one of the interfaces.
mount a /proc in each jail, it will make ps more useable.
/proc/<pid>/status tells the hostname of the prison for
jailed processes.
Quotas are only sensible if you have a mountpoint per prison.
There are no privisions for stopping resource-hogging.
Some "#ifdef INET" and similar may be missing (send patches!)
If somebody wants to take it from here and develop it into
more of a "virtual machine" they should be most welcome!
Tools, comments, patches & documentation most welcome.
Have fun...
Sponsored by: http://www.rndassociates.com/
Run for almost a year by: http://www.servetheweb.com/
transceiver. Note in the manual page that autoselection doesn't
work on the 82c168 because the built-in NWAY support is horribly
broken. Manual mode selection works fine, but autoneg is broken for
everything except maybe 10Mbps half-duplex. There's no simple way
to fix this at the moment, so I have to settle for documenting the
bug for now. Fortunately, there aren't anywhere near as many 82c168
boards around as there are 82c169s.
I changed to "Christopher G. Demetriou" since the page appears to be a
revision of lkm(4).
PR: docs/8611
Submitted by: Rajesh Vaidheeswarran <rv@fore.com>
