[CALL FOR TESTERS] Accounting implemented as separate kernel thread

[Wojciech A. Koszek]

Hello,

There were some problems in our current accounting implementation.
These were reported by Richard Todd:

http://lists.freebsd.org/pipermail/freebsd-current/2005-December/059149.html

I've decided to solve this problem and came up with implementation of
John Baldwin's idea: separate kernel thread responsible for acconting.
It is created when needed and destroyed when accounting is being
disabled. Also handles resume/suspend states. I did some tests and
couldn't get a panic.

The patch is here:
	http://freebsd.czest.pl/dunstan/FreeBSD/kern_acct.0.patch

It would be probably useful to replace current static SYSCTL_INTs and
replace them with SYSCTL_PROC of CTLTYPE_INT type in order to call
wakeup() just after configuration value change.

Comments are (as always) welcome!
-- 
* Wojciech A. Koszek && dunstan at FreeBSD.czest.pl