Re: [PATCH RFC tools/lkmm 10/12] tools/memory-model: Add a S lock-based external-view litmus test

From: Alan Stern
Date: Wed Feb 21 2018 - 13:38:45 EST


On Wed, 21 Feb 2018, Paul E. McKenney wrote:

> On Wed, Feb 21, 2018 at 11:50:31AM -0500, Alan Stern wrote:
> > On Wed, 21 Feb 2018, Paul E. McKenney wrote:
> >
> > > On Wed, Feb 21, 2018 at 10:09:00AM -0500, Alan Stern wrote:
> > > > On Tue, 20 Feb 2018, Paul E. McKenney wrote:
> > > >
> > > > > From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> > > > >
> > > > > This commit adds a litmus test in which P0() and P1() form a lock-based S
> > > > > litmus test, with the addition of P2(), which observes P0()'s and P1()'s
> > > >
> > > > Why do you call this an "S" litmus test? Isn't ISA2 a better
> > > > description?
> > >
> > > Indeed, the name of the test is in fact ISA2.
> >
> > Sure; and the Changelog entry should reflect this.
>
> No argument.

> ------------------------------------------------------------------------
>
> commit e6658d1d7fcc6391f3d00beaadc484243123a893
> Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
> Date: Wed Feb 21 09:49:01 2018 -0800
>
> tools/memory-order: Add documentation of new litmus test
>
> The litmus-tests/README file lacked any mention of then litmus test

s/lacked/lacks/
s/then/the new/

> named ISA2+pooncelock+pooncelock+pombonce.litmus. This commit therefore

s/named //

> adds this test.

It adds a description of the test, not the test itself.

>
> Reported-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
>
> diff --git a/tools/memory-model/litmus-tests/README b/tools/memory-model/litmus-tests/README
> index dca7d823ad57..aff3eb90e067 100644
> --- a/tools/memory-model/litmus-tests/README
> +++ b/tools/memory-model/litmus-tests/README
> @@ -32,6 +32,11 @@ IRIW+poonceonces+OnceOnce.litmus
> order of a pair of writes, where each write is to a different
> variable by a different process?
>
> +ISA2+pooncelock+pooncelock+pombonce.litmus
> + Tests whether the ordering provided by a lock-protected S litmus

Call it an ISA2 litmus test, not an S litmus test!

> + test is visible to an external process whose accesses are
> + separated by smp_mb().
> +
> ISA2+poonceonces.litmus
> As below, but with store-release replaced with WRITE_ONCE()
> and load-acquire replaced with READ_ONCE().

Alan