Re: [PATCH RFC memory-model 0/6] LKMM updates

Andrea Parri
2019-01-10T08:40:24Z

> > > > It seems that
> > > >
> > > > 1b52d0186177 ("tools/memory-model: Model smp_mb__after_unlock_lock()")
> > > >
> > > > from linux-rcu/dev got lost; this also needs an ack (probably yours! ;D,
> > > > considered that, IIRC, you introduced the primitive and RCU is currently
> > > > its only user.)
> > >
> > > That commit is in -tip:
> > >
> > > 4607abbcf464 ("tools/memory-model: Model smp_mb__after_unlock_lock()")
> > >
> > > So it has already left my -rcu tree. ;-)
> >
> > Oh, you're right: now I see the commit (e.g., with "git show"), but I
> > don't see the corresponding changes applied to the tree.
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=locking/core&id=4607abbcf464ea2be14da444215d05c73025cf6e
> > https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/tree/tools/memory-model/linux-kernel.bell?h=locking/core
> >
> > Is this expected?
>
> Are you asking why it is in -tip but not in mainline? I am not sure,
> but given that the merge window was over the holiday season and that
> the length of the merge window proved to be shorter than many people
> expected it to be, I am not too surprised. ;-)

Mmh, let me try again:

$ git clone git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git
$ cd tip
$ git checkout -b locking/core origin/locking/core

$ git show 4607abbcf464
commit 4607abbcf464ea2be14da444215d05c73025cf6e
Author: Andrea Parri <andrea.parri@amarulasolutions.com>
Date: Mon Dec 3 15:04:49 2018 -0800

tools/memory-model: Model smp_mb__after_unlock_lock()

$ cd tools/memory-model
$ herd7 -conf linux-kernel.cfg after-unlock-lock-same-cpu.litmus
File "after-unlock-lock-same-cpu.litmus": Unknown macro smp_mb__after_unlock_lock (User error)

[aka, linux-kernel.def in tip:locking/core does not have the
smp_mb__after_unlock_lock() added by 4607abbcf464]

Andrea

>
> Thanx, Paul
>