witness found wanting (was Re: LORs in ipfilter)

[Darren Reed]

On Sun, Dec 26, 2004 at 10:53:33PM +0200, Giorgos Keramidas wrote:
> 
> Is this performance hit FreeBSD specific?  I saw in ip_compat.h that on
> __sgi systems mutexes are used instead of rwlocks.

When I first ported IPFilter to IRIX, their equivalent of sx locks did
not work in interrupt context (I think this was also true of lockmgr
locks in BSD, too.)  To work around this, I used mutexes instead.

The #ifdef maze in 3.4's ip_compat.h is delicate so I try not to mess
with it more than I have to, but later versions of IRIX do have a working
lock type of this nature and I use it where available.

In this case, "do not work" means "panic when attempted".

Darren