From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH 13/13] rcutorture: formal: prepare for ACCESS_ONCE() removal
Date: Tue, 10 Oct 2017 05:47:12 -0700 [thread overview]
Message-ID: <20171010124712.GV3521@linux.vnet.ibm.com> (raw)
In-Reply-To: <20171010095413.GE27659@leverpostej>
On Tue, Oct 10, 2017 at 10:54:14AM +0100, Mark Rutland wrote:
> On Mon, Oct 09, 2017 at 12:51:12PM -0700, Paul E. McKenney wrote:
> > On Mon, Oct 09, 2017 at 07:28:50PM +0100, Mark Rutland wrote:
> > > diff --git a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h
> > > index 6687acc..ee4e4f8 100644
> > > --- a/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h
> > > +++ b/tools/testing/selftests/rcutorture/formal/srcu-cbmc/src/barriers.h
> > > @@ -34,8 +34,9 @@
> > > #define rs_smp_mb() do {} while (0)
> > > #endif
> > >
> > > -#define ACCESS_ONCE(x) (*(volatile typeof(x) *) &(x))
> > > -#define READ_ONCE(x) ACCESS_ONCE(x)
> > > -#define WRITE_ONCE(x, val) (ACCESS_ONCE(x) = (val))
> > > +#define __ACCESS_ONCE(x) (*(volatile typeof(x) *) &(x))
> > > +#define ACCESS_ONCE(x) __ACCESS_ONCE(x)
> > > +#define READ_ONCE(x) __ACCESS_ONCE(x)
> > > +#define WRITE_ONCE(x, val) (__ACCESS_ONCE(x) = (val))
> >
> > How about something like the following?
> >
> > #define READ_ONCE(x) (*(volatile typeof(x) *) &(x))
> > #define WRITE_ONCE(x) ((*(volatile typeof(x) *) &(x)) = (val))
>
> Sure; folded in and pushed out. :)
Thank you!
> I've assumed that the ACCESS_ONCE() definition needs to be kept until
> that's ripped out treewide. Please shout if that's not the case!
You have it right. This case is an exception because this code is
used only by RCU, which has long since had ACCESS_ONCE() ripped out.
Thanx, Paul
next prev parent reply other threads:[~2017-10-10 12:47 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-09 18:28 [PATCH 00/13] Preparatory work to kill off ACCESS_ONCE() Mark Rutland
2017-10-09 18:28 ` [PATCH 01/13] dm integrity: " Mark Rutland
2017-10-09 18:28 ` [PATCH 02/13] EDAC, altera: " Mark Rutland
2017-10-09 23:12 ` Thor Thayer
2017-10-10 9:30 ` Mark Rutland
2017-10-09 18:28 ` [PATCH 03/13] firmware/ivc: " Mark Rutland
2017-10-09 18:28 ` [PATCH 04/13] fs: dcache: " Mark Rutland
2017-10-09 18:28 ` [PATCH 05/13] fs: ncpfs: " Mark Rutland
2017-10-09 18:28 ` [PATCH 06/13] media: dvb_ringbuffer: " Mark Rutland
2017-10-09 18:28 ` [PATCH 07/13] net: netlink/netfilter: " Mark Rutland
2017-10-09 18:28 ` [PATCH 08/13] net/ipv4/tcp_input.c: " Mark Rutland
2017-10-09 19:03 ` Mark Rutland
2017-10-09 18:28 ` [PATCH 09/13] net: average: " Mark Rutland
2017-10-10 9:28 ` Mark Rutland
2017-10-09 18:28 ` [PATCH 10/13] samples: mic/mpssd/mpssd.c: " Mark Rutland
2017-10-09 18:28 ` [PATCH 11/13] selftests/powerpc: " Mark Rutland
2017-10-10 0:45 ` Michael Ellerman
2017-10-10 9:32 ` Mark Rutland
2017-10-09 18:28 ` [PATCH 12/13] workqueue: " Mark Rutland
2017-10-10 14:06 ` Tejun Heo
2017-10-10 16:21 ` Mark Rutland
2017-10-09 18:28 ` [PATCH 13/13] rcutorture: formal: prepare for ACCESS_ONCE() removal Mark Rutland
2017-10-09 19:51 ` Paul E. McKenney
2017-10-10 9:54 ` Mark Rutland
2017-10-10 12:47 ` Paul E. McKenney [this message]
2017-10-10 12:50 ` Mark Rutland
2017-10-10 14:52 ` Paul E. McKenney
2017-10-10 16:24 ` Mark Rutland
2017-10-10 16:35 ` Paul E. McKenney
2017-10-10 16:27 ` Joe Perches
2017-10-10 16:35 ` Paul E. McKenney
2017-10-10 16:41 ` Mark Rutland
2017-10-10 16:57 ` Joe Perches
2017-10-10 17:06 ` Mark Rutland
2017-10-09 20:02 ` [PATCH 00/13] Preparatory work to kill off ACCESS_ONCE() Paul E. McKenney
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