PERFORCE change 126330 for review

[Pawel Jakub Dawidek]

On Thu, Sep 13, 2007 at 12:30:26AM +0200, Attilio Rao wrote:
> 2007/9/12, Kip Macy <kip.macy at gmail.com>:
> > On 9/12/07, Pawel Jakub Dawidek <pjd at freebsd.org> wrote:
> > > On Wed, Sep 12, 2007 at 08:32:21AM +0000, Kip Macy wrote:
> > > > http://perforce.freebsd.org/chv.cgi?CH=126330
> > > >
> > > > Change 126330 by kmacy at kmacy_home:ethng on 2007/09/12 08:31:36
> > > >
> > > >       convert radix node head and route locks from mutexes to rwlocks
> > > [...]
> > > >               rt->rt_flags |= RTF_LLINFO;
> > > > -             callout_init_mtx(&la->la_timer, &rt->rt_mtx,
> > > > -                 CALLOUT_RETURNUNLOCKED);
> > > > +             callout_init_rwlock(&la->la_timer, &rt->rt_lock,
> > > > +                 CALLOUT_RETURNUNLOCKED_RW);
> > > >
> > >
> > > Kip, don't add callout_init_rwlock() to the tree. I've
> > > callout_init_lock() implemented that operates on any lock type, just
> > > like condvar(9).
> >
> > point me to a diff
> 
> I'm courious to know another thing instead.
> As like condvar() works, it is allowed to before release and later
> acquire the lock.
> This scheme let you acquire the lock again following the previous
> pattern for sx and rw locks (if for example you had a rwlock mantained
> in write mode you will acquire it in the same way).
> This is not applicable to callout, instead, as you have the lock
> 'blank', so with double-kind locks (like rw and sx) how do you lock
> it?

Always write/exclusive.

-- 
Pawel Jakub Dawidek                       http://www.wheel.pl
pjd at FreeBSD.org                           http://www.FreeBSD.org
FreeBSD committer                         Am I Evil? Yes, I Am!
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