rwlock patch to prefer writers and improve spinning.

[Gary Jennejohn]

On Wed, 30 Jan 2008 14:56:05 -1000 (HST)
Jeff Roberson <jroberson at chesapeake.net> wrote:

> On Wed, 30 Jan 2008, Attilio Rao wrote:
> >>> Jeff,
> >>> it is not missing a kern/subr_witness.c part where some checks are axed out?
> >>
> >> Oh you are right I forgot to include some turnstile pieces as well.  I
> >> will provide them soon.
> >
> > Gah, I meant kern/subr_turnstile.c really :)
> 
> The patch is updated in place at:
> 
> http://people.freebsd.org/~jeff/rwlock.diff
> 

Doesn't apply cleanly against -current updated about 10 minutes ago:

Hunk #22 failed at 797.
1 out of 22 hunks failed--saving rejects to kern/kern_rwlock.c.rej

I have
__FBSDID("$FreeBSD: src/sys/kern/kern_rwlock.c,v 1.34 2008/01/17 20:15:15 jhb
Exp $");

Easy enough to apply by hand, but still...

---
Gary Jennejohn