Re: [PATCH] tools/memory-model: remove rb-dep, smp_read_barrier_depends, and lockless_dereference
From: Paul E. McKenney
Date: Wed Feb 21 2018 - 11:05:58 EST
On Wed, Feb 21, 2018 at 10:00:20AM -0500, Alan Stern wrote:
> On Fri, 16 Feb 2018, Paul E. McKenney wrote:
>
> > On Fri, Feb 16, 2018 at 05:22:55PM -0500, Alan Stern wrote:
> > > Since commit 76ebbe78f739 ("locking/barriers: Add implicit
> > > smp_read_barrier_depends() to READ_ONCE()") was merged for the 4.15
> > > kernel, it has not been necessary to use smp_read_barrier_depends().
> > > Similarly, commit 59ecbbe7b31c ("locking/barriers: Kill
> > > lockless_dereference()") removed lockless_dereference() from the
> > > kernel.
> > >
> > > Since these primitives are no longer part of the kernel, they do not
> > > belong in the Linux Kernel Memory Consistency Model. This patch
> > > removes them, along with the internal rb-dep relation, and updates the
> > > revelant documentation.
> > >
> > > Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> >
> > I queued this, but would welcome an update that addressed Akira's
> > feedback as appropriate.
>
> Is it too late to send a v2 of this patch? I didn't want to do it
> before now because the issue raised by Andrea wasn't settled. (Some
> could claim that it still isn't fully settled...)
Would you be willing to send a delta patch? I can then place it directly
on top of your original patch, and once it settles out, I can ask Ingo
if he is willing to update the patch in -tip.
Thanx, Paul