Re: [PATCH 1/3] tools: memory-model: Prepare for data-race detection

From: Paul E. McKenney
Date: Wed Apr 24 2019 - 14:31:18 EST


On Wed, Apr 24, 2019 at 10:24:42AM -0400, Alan Stern wrote:
> On Wed, 24 Apr 2019, Paul E. McKenney wrote:
>
> > On Mon, Apr 22, 2019 at 12:17:45PM -0400, Alan Stern wrote:
> > > This patch makes some slight alterations to linux-kernel.cat in
> > > preparation for adding support for data-race detection to the
> > > Linux-Kernel Memory Model.
> > >
> > > The definitions of relations involved in Acquire, Release, and
> > > unlock-lock ordering are moved up earlier in the source file.
> > >
> > > The rmb relation is factored through the new R4rmb class: the
> > > class of reads to which rmb will apply.
> > >
> > > The definition of the fence relation is moved earlier, and it
> > > is split up into read- and write-fences (rmb and wmb) and all
> > > the others.
> > >
> > > This should not make any functional changes.
> > >
> > > Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> >
> > Thank you, Alan, I have queued all three onto -rcu for review and testing.
> > FYI, I rebased my smp_mb__{before,after}_atomic() patch on top of yours
> > to avoid the conflict.
> >
> > Which demonstrates non-commutativity of patches. Your patches conflict
> > with mine, but mine does not conflict with yours. ;-)
>
> :-)
>
> Besides, who knows where we'll end up with the
> smp_mb__{before,after}_atomic stuff once Peter is done with it, anyway?

True enough!

Thanx, Paul