Re: memory-barriers.txt again (was Re: [PATCH 4/9] firewire: don't use PREPARE_DELAYED_WORK)

From: Paul E. McKenney
Date: Mon Feb 24 2014 - 11:27:46 EST


On Mon, Feb 24, 2014 at 01:32:54AM +0100, Stefan Richter wrote:
> On Feb 23 Paul E. McKenney wrote:
> >>> Please see below for a patch against the current version of
> >>> Documentation/memory-barriers.txt. Does this update help?
>
> Thank you, this clarifies it.
>
> [...]
> A new nit:
> > +The operations will always occur in one of the following orders:
> >
> > - STORE *A, RELEASE, ACQUIRE, STORE *B
> > - STORE *A, ACQUIRE, RELEASE, STORE *B
> > + STORE *A, RELEASE, ACQUIRE, smp_mb__after_unlock_lock(), STORE *B
> > + STORE *A, ACQUIRE, RELEASE, smp_mb__after_unlock_lock(), STORE *B
> > + ACQUIRE, STORE *A, RELEASE, smp_mb__after_unlock_lock(), STORE *B
> >
> > -If the RELEASE and ACQUIRE were instead both operating on the same lock
> > -variable, only the first of these two alternatives can occur.
> > +If the RELEASE and ACQUIRE were instead both operating on the
> > +same lock variable, only the first of these two alternatives can
> > +occur.
> ^^^
> ...these {,three} alternatives...

Good catch! I chose the empty string.

Thanx, Paul

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/