Date: Sat, 1 Nov 2014 00:35:02 +0100 From: Mateusz Guzik <mjguzik@gmail.com> To: John Baldwin <jhb@freebsd.org> Cc: John-Mark Gurney <jmg@funkthat.com>, freebsd-arch@freebsd.org Subject: Re: refcount_release_take_##lock Message-ID: <20141031233502.GB20591@dft-labs.eu> In-Reply-To: <20141028193404.GB12014@dft-labs.eu> References: <20141025184448.GA19066@dft-labs.eu> <201410281154.54581.jhb@freebsd.org> <20141028174428.GA12014@dft-labs.eu> <201410281413.58414.jhb@freebsd.org> <20141028193404.GB12014@dft-labs.eu>
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On Tue, Oct 28, 2014 at 08:34:04PM +0100, Mateusz Guzik wrote: > On Tue, Oct 28, 2014 at 02:13:58PM -0400, John Baldwin wrote: > > On Tuesday, October 28, 2014 1:44:28 pm Mateusz Guzik wrote: > > > diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c > > > index f8ae0e6..e94ccde 100644 > > > --- a/sys/kern/kern_jail.c > > > +++ b/sys/kern/kern_jail.c > > > > The diff looks good to me. Just need to update refcount.9 as well. > > > Ping? Is this diff ok? > diff --git a/share/man/man9/refcount.9 b/share/man/man9/refcount.9 > index e7702a2..61b9b51 100644 > --- a/share/man/man9/refcount.9 > +++ b/share/man/man9/refcount.9 > @@ -26,7 +26,7 @@ > .\" > .\" $FreeBSD$ > .\" > -.Dd January 20, 2009 > +.Dd October 28, 2014 > .Dt REFCOUNT 9 > .Os > .Sh NAME > @@ -44,6 +44,15 @@ > .Fn refcount_acquire "volatile u_int *count" > .Ft int > .Fn refcount_release "volatile u_int *count" > +.In sys/mutex.h > +.Fn refcount_release_lock_mtx "volatile u_int *count, struct mtx *lock" > +.In sys/rmlock.h > +.Fn refcount_release_lock_rmlock "volatile u_int *count, struct rmlock *lock" > +.In sys/rwlock.h > +.Fn refcount_release_lock_rwlock "volatile u_int *count, struct rwlock *lock" > +.In sys/lock.h > +.In sys/sx.h > +.Fn refcount_release_lock_sx "volatile u_int *count, struct sx *lock" > .Sh DESCRIPTION > The > .Nm > @@ -77,6 +86,13 @@ The function returns a non-zero value if the reference being released was > the last reference; > otherwise, it returns zero. > .Pp > +.Fn refcount_release_lock_* > +functions release an existing reference holding the lock if it is the last > +reference. > +These functions return with the lock held and a non-zero value if the reference > +being released was the last reference; > +otherwise, they returns zero and the lock is not held. > +.Pp > Note that these routines do not provide any inter-CPU synchronization, > data protection, > or memory ordering guarantees except for managing the counter. > @@ -91,6 +107,18 @@ The > .Nm refcount_release > function returns non-zero when releasing the last reference and zero when > releasing any other reference. > +.Pp > +.Nm refcount_release_lock_* > +functions return with the lock held and non-zero value when releasing the last > +reference, zero without the lock held when releasing any other reference. > .Sh HISTORY > -These functions were introduced in > +.Fn refcount_init , > +.Fn refcount_acquire > +and > +.Fn refcount_release > +functions were introduced in > .Fx 6.0 . > +.Pp > +.Fn refcount_release_lock_* > +functions were introduced in > +.Fx 10.2 . > > -- > Mateusz Guzik <mjguzik gmail.com> -- Mateusz Guzik <mjguzik gmail.com>
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