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Message-Id: <20180529180100.GN3803@linux.vnet.ibm.com>
Date: Tue, 29 May 2018 11:01:00 -0700
From: "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To: Andrea Parri <andrea.parri@...rulasolutions.com>
Cc: linux-kernel@...r.kernel.org,
Alan Stern <stern@...land.harvard.edu>,
Will Deacon <will.deacon@....com>,
Peter Zijlstra <peterz@...radead.org>,
Boqun Feng <boqun.feng@...il.com>,
Nicholas Piggin <npiggin@...il.com>,
David Howells <dhowells@...hat.com>,
Jade Alglave <j.alglave@....ac.uk>,
Luc Maranget <luc.maranget@...ia.fr>,
Akira Yokosawa <akiyks@...il.com>
Subject: Re: [PATCH] tools/memory-model: Rename litmus tests to comply to
norm7
On Tue, May 29, 2018 at 02:20:13PM +0200, Andrea Parri wrote:
> norm7 produces the 'normalized' name of a litmus test, when the test
> can be generated from a single cycle that passes through each process
> exactly once. The commit renames such tests in order to comply to the
> naming scheme implemented by this tool.
>
> Signed-off-by: Andrea Parri <andrea.parri@...rulasolutions.com>
Queued and pushed, most likely for 4.19, thank you!
Thanx, Paul
> Cc: Alan Stern <stern@...land.harvard.edu>
> Cc: Will Deacon <will.deacon@....com>
> Cc: Peter Zijlstra <peterz@...radead.org>
> Cc: Boqun Feng <boqun.feng@...il.com>
> Cc: Nicholas Piggin <npiggin@...il.com>
> Cc: David Howells <dhowells@...hat.com>
> Cc: Jade Alglave <j.alglave@....ac.uk>
> Cc: Luc Maranget <luc.maranget@...ia.fr>
> Cc: "Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
> Cc: Akira Yokosawa <akiyks@...il.com>
> ---
> tools/memory-model/Documentation/recipes.txt | 8 ++--
> tools/memory-model/README | 20 +++++-----
> .../IRIW+fencembonceonces+OnceOnce.litmus | 45 ++++++++++++++++++++++
> .../litmus-tests/IRIW+mbonceonces+OnceOnce.litmus | 45 ----------------------
> .../litmus-tests/LB+ctrlonceonce+mbonceonce.litmus | 34 ----------------
> .../LB+fencembonceonce+ctrlonceonce.litmus | 34 ++++++++++++++++
> .../MP+fencewmbonceonce+fencermbonceonce.litmus | 30 +++++++++++++++
> .../litmus-tests/MP+wmbonceonce+rmbonceonce.litmus | 30 ---------------
> .../litmus-tests/R+fencembonceonces.litmus | 30 +++++++++++++++
> .../memory-model/litmus-tests/R+mbonceonces.litmus | 30 ---------------
> tools/memory-model/litmus-tests/README | 16 ++++----
> .../S+fencewmbonceonce+poacquireonce.litmus | 27 +++++++++++++
> .../S+wmbonceonce+poacquireonce.litmus | 27 -------------
> .../litmus-tests/SB+fencembonceonces.litmus | 32 +++++++++++++++
> .../litmus-tests/SB+mbonceonces.litmus | 32 ---------------
> .../WRC+pooncerelease+fencermbonceonce+Once.litmus | 38 ++++++++++++++++++
> .../WRC+pooncerelease+rmbonceonce+Once.litmus | 38 ------------------
> ...release+poacquirerelease+fencembonceonce.litmus | 42 ++++++++++++++++++++
> ...ooncerelease+poacquirerelease+mbonceonce.litmus | 42 --------------------
> 19 files changed, 300 insertions(+), 300 deletions(-)
> create mode 100644 tools/memory-model/litmus-tests/IRIW+fencembonceonces+OnceOnce.litmus
> delete mode 100644 tools/memory-model/litmus-tests/IRIW+mbonceonces+OnceOnce.litmus
> delete mode 100644 tools/memory-model/litmus-tests/LB+ctrlonceonce+mbonceonce.litmus
> create mode 100644 tools/memory-model/litmus-tests/LB+fencembonceonce+ctrlonceonce.litmus
> create mode 100644 tools/memory-model/litmus-tests/MP+fencewmbonceonce+fencermbonceonce.litmus
> delete mode 100644 tools/memory-model/litmus-tests/MP+wmbonceonce+rmbonceonce.litmus
> create mode 100644 tools/memory-model/litmus-tests/R+fencembonceonces.litmus
> delete mode 100644 tools/memory-model/litmus-tests/R+mbonceonces.litmus
> create mode 100644 tools/memory-model/litmus-tests/S+fencewmbonceonce+poacquireonce.litmus
> delete mode 100644 tools/memory-model/litmus-tests/S+wmbonceonce+poacquireonce.litmus
> create mode 100644 tools/memory-model/litmus-tests/SB+fencembonceonces.litmus
> delete mode 100644 tools/memory-model/litmus-tests/SB+mbonceonces.litmus
> create mode 100644 tools/memory-model/litmus-tests/WRC+pooncerelease+fencermbonceonce+Once.litmus
> delete mode 100644 tools/memory-model/litmus-tests/WRC+pooncerelease+rmbonceonce+Once.litmus
> create mode 100644 tools/memory-model/litmus-tests/Z6.0+pooncerelease+poacquirerelease+fencembonceonce.litmus
> delete mode 100644 tools/memory-model/litmus-tests/Z6.0+pooncerelease+poacquirerelease+mbonceonce.litmus
>
> diff --git a/tools/memory-model/Documentation/recipes.txt b/tools/memory-model/Documentation/recipes.txt
> index ee4309a87fc45..a40802fa1099e 100644
> --- a/tools/memory-model/Documentation/recipes.txt
> +++ b/tools/memory-model/Documentation/recipes.txt
> @@ -126,7 +126,7 @@ However, it is not necessarily the case that accesses ordered by
> locking will be seen as ordered by CPUs not holding that lock.
> Consider this example:
>
> - /* See Z6.0+pooncelock+pooncelock+pombonce.litmus. */
> + /* See Z6.0+pooncerelease+poacquirerelease+fencembonceonce.litmus. */
> void CPU0(void)
> {
> spin_lock(&mylock);
> @@ -292,7 +292,7 @@ and to use smp_load_acquire() instead of smp_rmb(). However, the older
> smp_wmb() and smp_rmb() APIs are still heavily used, so it is important
> to understand their use cases. The general approach is shown below:
>
> - /* See MP+wmbonceonce+rmbonceonce.litmus. */
> + /* See MP+fencewmbonceonce+fencermbonceonce.litmus. */
> void CPU0(void)
> {
> WRITE_ONCE(x, 1);
> @@ -360,7 +360,7 @@ can be seen in the LB+poonceonces.litmus litmus test.
> One way of avoiding the counter-intuitive outcome is through the use of a
> control dependency paired with a full memory barrier:
>
> - /* See LB+ctrlonceonce+mbonceonce.litmus. */
> + /* See LB+fencembonceonce+ctrlonceonce.litmus. */
> void CPU0(void)
> {
> r0 = READ_ONCE(x);
> @@ -476,7 +476,7 @@ that one CPU first stores to one variable and then loads from a second,
> while another CPU stores to the second variable and then loads from the
> first. Preserving order requires nothing less than full barriers:
>
> - /* See SB+mbonceonces.litmus. */
> + /* See SB+fencembonceonces.litmus. */
> void CPU0(void)
> {
> WRITE_ONCE(x, 1);
> diff --git a/tools/memory-model/README b/tools/memory-model/README
> index 734f7feaa5dc5..ee987ce20aaec 100644
> --- a/tools/memory-model/README
> +++ b/tools/memory-model/README
> @@ -35,13 +35,13 @@ BASIC USAGE: HERD7
> The memory model is used, in conjunction with "herd7", to exhaustively
> explore the state space of small litmus tests.
>
> -For example, to run SB+mbonceonces.litmus against the memory model:
> +For example, to run SB+fencembonceonces.litmus against the memory model:
>
> - $ herd7 -conf linux-kernel.cfg litmus-tests/SB+mbonceonces.litmus
> + $ herd7 -conf linux-kernel.cfg litmus-tests/SB+fencembonceonces.litmus
>
> Here is the corresponding output:
>
> - Test SB+mbonceonces Allowed
> + Test SB+fencembonceonces Allowed
> States 3
> 0:r0=0; 1:r0=1;
> 0:r0=1; 1:r0=0;
> @@ -50,8 +50,8 @@ Here is the corresponding output:
> Witnesses
> Positive: 0 Negative: 3
> Condition exists (0:r0=0 /\ 1:r0=0)
> - Observation SB+mbonceonces Never 0 3
> - Time SB+mbonceonces 0.01
> + Observation SB+fencembonceonces Never 0 3
> + Time SB+fencembonceonces 0.01
> Hash=d66d99523e2cac6b06e66f4c995ebb48
>
> The "Positive: 0 Negative: 3" and the "Never 0 3" each indicate that
> @@ -67,16 +67,16 @@ BASIC USAGE: KLITMUS7
> The "klitmus7" tool converts a litmus test into a Linux kernel module,
> which may then be loaded and run.
>
> -For example, to run SB+mbonceonces.litmus against hardware:
> +For example, to run SB+fencembonceonces.litmus against hardware:
>
> $ mkdir mymodules
> - $ klitmus7 -o mymodules litmus-tests/SB+mbonceonces.litmus
> + $ klitmus7 -o mymodules litmus-tests/SB+fencembonceonces.litmus
> $ cd mymodules ; make
> $ sudo sh run.sh
>
> The corresponding output includes:
>
> - Test SB+mbonceonces Allowed
> + Test SB+fencembonceonces Allowed
> Histogram (3 states)
> 644580 :>0:r0=1; 1:r0=0;
> 644328 :>0:r0=0; 1:r0=1;
> @@ -86,8 +86,8 @@ The corresponding output includes:
> Positive: 0, Negative: 2000000
> Condition exists (0:r0=0 /\ 1:r0=0) is NOT validated
> Hash=d66d99523e2cac6b06e66f4c995ebb48
> - Observation SB+mbonceonces Never 0 2000000
> - Time SB+mbonceonces 0.16
> + Observation SB+fencembonceonces Never 0 2000000
> + Time SB+fencembonceonces 0.16
>
> The "Positive: 0 Negative: 2000000" and the "Never 0 2000000" indicate
> that during two million trials, the state specified in this litmus
> diff --git a/tools/memory-model/litmus-tests/IRIW+fencembonceonces+OnceOnce.litmus b/tools/memory-model/litmus-tests/IRIW+fencembonceonces+OnceOnce.litmus
> new file mode 100644
> index 0000000000000..e729d2776e89a
> --- /dev/null
> +++ b/tools/memory-model/litmus-tests/IRIW+fencembonceonces+OnceOnce.litmus
> @@ -0,0 +1,45 @@
> +C IRIW+fencembonceonces+OnceOnce
> +
> +(*
> + * Result: Never
> + *
> + * Test of independent reads from independent writes with smp_mb()
> + * between each pairs of reads. In other words, is smp_mb() sufficient to
> + * cause two different reading processes to agree on the order of a pair
> + * of writes, where each write is to a different variable by a different
> + * process? This litmus test exercises LKMM's "propagation" rule.
> + *)
> +
> +{}
> +
> +P0(int *x)
> +{
> + WRITE_ONCE(*x, 1);
> +}
> +
> +P1(int *x, int *y)
> +{
> + int r0;
> + int r1;
> +
> + r0 = READ_ONCE(*x);
> + smp_mb();
> + r1 = READ_ONCE(*y);
> +}
> +
> +P2(int *y)
> +{
> + WRITE_ONCE(*y, 1);
> +}
> +
> +P3(int *x, int *y)
> +{
> + int r0;
> + int r1;
> +
> + r0 = READ_ONCE(*y);
> + smp_mb();
> + r1 = READ_ONCE(*x);
> +}
> +
> +exists (1:r0=1 /\ 1:r1=0 /\ 3:r0=1 /\ 3:r1=0)
> diff --git a/tools/memory-model/litmus-tests/IRIW+mbonceonces+OnceOnce.litmus b/tools/memory-model/litmus-tests/IRIW+mbonceonces+OnceOnce.litmus
> deleted file mode 100644
> index 98a3716efa37e..0000000000000
> --- a/tools/memory-model/litmus-tests/IRIW+mbonceonces+OnceOnce.litmus
> +++ /dev/null
> @@ -1,45 +0,0 @@
> -C IRIW+mbonceonces+OnceOnce
> -
> -(*
> - * Result: Never
> - *
> - * Test of independent reads from independent writes with smp_mb()
> - * between each pairs of reads. In other words, is smp_mb() sufficient to
> - * cause two different reading processes to agree on the order of a pair
> - * of writes, where each write is to a different variable by a different
> - * process? This litmus test exercises LKMM's "propagation" rule.
> - *)
> -
> -{}
> -
> -P0(int *x)
> -{
> - WRITE_ONCE(*x, 1);
> -}
> -
> -P1(int *x, int *y)
> -{
> - int r0;
> - int r1;
> -
> - r0 = READ_ONCE(*x);
> - smp_mb();
> - r1 = READ_ONCE(*y);
> -}
> -
> -P2(int *y)
> -{
> - WRITE_ONCE(*y, 1);
> -}
> -
> -P3(int *x, int *y)
> -{
> - int r0;
> - int r1;
> -
> - r0 = READ_ONCE(*y);
> - smp_mb();
> - r1 = READ_ONCE(*x);
> -}
> -
> -exists (1:r0=1 /\ 1:r1=0 /\ 3:r0=1 /\ 3:r1=0)
> diff --git a/tools/memory-model/litmus-tests/LB+ctrlonceonce+mbonceonce.litmus b/tools/memory-model/litmus-tests/LB+ctrlonceonce+mbonceonce.litmus
> deleted file mode 100644
> index de6708229dd11..0000000000000
> --- a/tools/memory-model/litmus-tests/LB+ctrlonceonce+mbonceonce.litmus
> +++ /dev/null
> @@ -1,34 +0,0 @@
> -C LB+ctrlonceonce+mbonceonce
> -
> -(*
> - * Result: Never
> - *
> - * This litmus test demonstrates that lightweight ordering suffices for
> - * the load-buffering pattern, in other words, preventing all processes
> - * reading from the preceding process's write. In this example, the
> - * combination of a control dependency and a full memory barrier are enough
> - * to do the trick. (But the full memory barrier could be replaced with
> - * another control dependency and order would still be maintained.)
> - *)
> -
> -{}
> -
> -P0(int *x, int *y)
> -{
> - int r0;
> -
> - r0 = READ_ONCE(*x);
> - if (r0)
> - WRITE_ONCE(*y, 1);
> -}
> -
> -P1(int *x, int *y)
> -{
> - int r0;
> -
> - r0 = READ_ONCE(*y);
> - smp_mb();
> - WRITE_ONCE(*x, 1);
> -}
> -
> -exists (0:r0=1 /\ 1:r0=1)
> diff --git a/tools/memory-model/litmus-tests/LB+fencembonceonce+ctrlonceonce.litmus b/tools/memory-model/litmus-tests/LB+fencembonceonce+ctrlonceonce.litmus
> new file mode 100644
> index 0000000000000..4727f5aaf03b0
> --- /dev/null
> +++ b/tools/memory-model/litmus-tests/LB+fencembonceonce+ctrlonceonce.litmus
> @@ -0,0 +1,34 @@
> +C LB+fencembonceonce+ctrlonceonce
> +
> +(*
> + * Result: Never
> + *
> + * This litmus test demonstrates that lightweight ordering suffices for
> + * the load-buffering pattern, in other words, preventing all processes
> + * reading from the preceding process's write. In this example, the
> + * combination of a control dependency and a full memory barrier are enough
> + * to do the trick. (But the full memory barrier could be replaced with
> + * another control dependency and order would still be maintained.)
> + *)
> +
> +{}
> +
> +P0(int *x, int *y)
> +{
> + int r0;
> +
> + r0 = READ_ONCE(*x);
> + if (r0)
> + WRITE_ONCE(*y, 1);
> +}
> +
> +P1(int *x, int *y)
> +{
> + int r0;
> +
> + r0 = READ_ONCE(*y);
> + smp_mb();
> + WRITE_ONCE(*x, 1);
> +}
> +
> +exists (0:r0=1 /\ 1:r0=1)
> diff --git a/tools/memory-model/litmus-tests/MP+fencewmbonceonce+fencermbonceonce.litmus b/tools/memory-model/litmus-tests/MP+fencewmbonceonce+fencermbonceonce.litmus
> new file mode 100644
> index 0000000000000..a273da9faa6d3
> --- /dev/null
> +++ b/tools/memory-model/litmus-tests/MP+fencewmbonceonce+fencermbonceonce.litmus
> @@ -0,0 +1,30 @@
> +C MP+fencewmbonceonce+fencermbonceonce
> +
> +(*
> + * Result: Never
> + *
> + * This litmus test demonstrates that smp_wmb() and smp_rmb() provide
> + * sufficient ordering for the message-passing pattern. However, it
> + * is usually better to use smp_store_release() and smp_load_acquire().
> + *)
> +
> +{}
> +
> +P0(int *x, int *y)
> +{
> + WRITE_ONCE(*x, 1);
> + smp_wmb();
> + WRITE_ONCE(*y, 1);
> +}
> +
> +P1(int *x, int *y)
> +{
> + int r0;
> + int r1;
> +
> + r0 = READ_ONCE(*y);
> + smp_rmb();
> + r1 = READ_ONCE(*x);
> +}
> +
> +exists (1:r0=1 /\ 1:r1=0)
> diff --git a/tools/memory-model/litmus-tests/MP+wmbonceonce+rmbonceonce.litmus b/tools/memory-model/litmus-tests/MP+wmbonceonce+rmbonceonce.litmus
> deleted file mode 100644
> index c078f38ff27ac..0000000000000
> --- a/tools/memory-model/litmus-tests/MP+wmbonceonce+rmbonceonce.litmus
> +++ /dev/null
> @@ -1,30 +0,0 @@
> -C MP+wmbonceonce+rmbonceonce
> -
> -(*
> - * Result: Never
> - *
> - * This litmus test demonstrates that smp_wmb() and smp_rmb() provide
> - * sufficient ordering for the message-passing pattern. However, it
> - * is usually better to use smp_store_release() and smp_load_acquire().
> - *)
> -
> -{}
> -
> -P0(int *x, int *y)
> -{
> - WRITE_ONCE(*x, 1);
> - smp_wmb();
> - WRITE_ONCE(*y, 1);
> -}
> -
> -P1(int *x, int *y)
> -{
> - int r0;
> - int r1;
> -
> - r0 = READ_ONCE(*y);
> - smp_rmb();
> - r1 = READ_ONCE(*x);
> -}
> -
> -exists (1:r0=1 /\ 1:r1=0)
> diff --git a/tools/memory-model/litmus-tests/R+fencembonceonces.litmus b/tools/memory-model/litmus-tests/R+fencembonceonces.litmus
> new file mode 100644
> index 0000000000000..222a0b850b4a5
> --- /dev/null
> +++ b/tools/memory-model/litmus-tests/R+fencembonceonces.litmus
> @@ -0,0 +1,30 @@
> +C R+fencembonceonces
> +
> +(*
> + * Result: Never
> + *
> + * This is the fully ordered (via smp_mb()) version of one of the classic
> + * counterintuitive litmus tests that illustrates the effects of store
> + * propagation delays. Note that weakening either of the barriers would
> + * cause the resulting test to be allowed.
> + *)
> +
> +{}
> +
> +P0(int *x, int *y)
> +{
> + WRITE_ONCE(*x, 1);
> + smp_mb();
> + WRITE_ONCE(*y, 1);
> +}
> +
> +P1(int *x, int *y)
> +{
> + int r0;
> +
> + WRITE_ONCE(*y, 2);
> + smp_mb();
> + r0 = READ_ONCE(*x);
> +}
> +
> +exists (y=2 /\ 1:r0=0)
> diff --git a/tools/memory-model/litmus-tests/R+mbonceonces.litmus b/tools/memory-model/litmus-tests/R+mbonceonces.litmus
> deleted file mode 100644
> index a0e884ad21321..0000000000000
> --- a/tools/memory-model/litmus-tests/R+mbonceonces.litmus
> +++ /dev/null
> @@ -1,30 +0,0 @@
> -C R+mbonceonces
> -
> -(*
> - * Result: Never
> - *
> - * This is the fully ordered (via smp_mb()) version of one of the classic
> - * counterintuitive litmus tests that illustrates the effects of store
> - * propagation delays. Note that weakening either of the barriers would
> - * cause the resulting test to be allowed.
> - *)
> -
> -{}
> -
> -P0(int *x, int *y)
> -{
> - WRITE_ONCE(*x, 1);
> - smp_mb();
> - WRITE_ONCE(*y, 1);
> -}
> -
> -P1(int *x, int *y)
> -{
> - int r0;
> -
> - WRITE_ONCE(*y, 2);
> - smp_mb();
> - r0 = READ_ONCE(*x);
> -}
> -
> -exists (y=2 /\ 1:r0=0)
> diff --git a/tools/memory-model/litmus-tests/README b/tools/memory-model/litmus-tests/README
> index 9c0ea65c53621..a41b027234286 100644
> --- a/tools/memory-model/litmus-tests/README
> +++ b/tools/memory-model/litmus-tests/README
> @@ -20,7 +20,7 @@ CoWW+poonceonce.litmus
> Test of write-write coherence, that is, whether or not two
> successive writes to the same variable are ordered.
>
> -IRIW+mbonceonces+OnceOnce.litmus
> +IRIW+fencembonceonces+OnceOnce.litmus
> Test of independent reads from independent writes with smp_mb()
> between each pairs of reads. In other words, is smp_mb()
> sufficient to cause two different reading processes to agree on
> @@ -49,7 +49,7 @@ ISA2+pooncerelease+poacquirerelease+poacquireonce.litmus
> Can a release-acquire chain order a prior store against
> a later load?
>
> -LB+ctrlonceonce+mbonceonce.litmus
> +LB+fencembonceonce+ctrlonceonce.litmus
> Does a control dependency and an smp_mb() suffice for the
> load-buffering litmus test, where each process reads from one
> of two variables then writes to the other?
> @@ -90,14 +90,14 @@ MP+porevlocks.litmus
> As below, but with the first access of the writer process
> and the second access of reader process protected by a lock.
>
> -MP+wmbonceonce+rmbonceonce.litmus
> +MP+fencewmbonceonce+fencermbonceonce.litmus
> Does a smp_wmb() (between the stores) and an smp_rmb() (between
> the loads) suffice for the message-passing litmus test, where one
> process writes data and then a flag, and the other process reads
> the flag and then the data. (This is similar to the ISA2 tests,
> but with two processes instead of three.)
>
> -R+mbonceonces.litmus
> +R+fencembonceonces.litmus
> This is the fully ordered (via smp_mb()) version of one of
> the classic counterintuitive litmus tests that illustrates the
> effects of store propagation delays.
> @@ -105,7 +105,7 @@ R+mbonceonces.litmus
> R+poonceonces.litmus
> As above, but without the smp_mb() invocations.
>
> -SB+mbonceonces.litmus
> +SB+fencembonceonces.litmus
> This is the fully ordered (again, via smp_mb() version of store
> buffering, which forms the core of Dekker's mutual-exclusion
> algorithm.
> @@ -125,12 +125,12 @@ SB+rfionceonce-poonceonces.litmus
> S+poonceonces.litmus
> As below, but without the smp_wmb() and acquire load.
>
> -S+wmbonceonce+poacquireonce.litmus
> +S+fencewmbonceonce+poacquireonce.litmus
> Can a smp_wmb(), instead of a release, and an acquire order
> a prior store against a subsequent store?
>
> WRC+poonceonces+Once.litmus
> -WRC+pooncerelease+rmbonceonce+Once.litmus
> +WRC+pooncerelease+fencermbonceonce+Once.litmus
> These two are members of an extension of the MP litmus-test
> class in which the first write is moved to a separate process.
> The second is forbidden because smp_store_release() is
> @@ -145,7 +145,7 @@ Z6.0+pooncelock+poonceLock+pombonce.litmus
> As above, but with smp_mb__after_spinlock() immediately
> following the spin_lock().
>
> -Z6.0+pooncerelease+poacquirerelease+mbonceonce.litmus
> +Z6.0+pooncerelease+poacquirerelease+fencembonceonce.litmus
> Is the ordering provided by a release-acquire chain sufficient
> to make ordering apparent to accesses by a process that does
> not participate in that release-acquire chain?
> diff --git a/tools/memory-model/litmus-tests/S+fencewmbonceonce+poacquireonce.litmus b/tools/memory-model/litmus-tests/S+fencewmbonceonce+poacquireonce.litmus
> new file mode 100644
> index 0000000000000..18479823cd6cc
> --- /dev/null
> +++ b/tools/memory-model/litmus-tests/S+fencewmbonceonce+poacquireonce.litmus
> @@ -0,0 +1,27 @@
> +C S+fencewmbonceonce+poacquireonce
> +
> +(*
> + * Result: Never
> + *
> + * Can a smp_wmb(), instead of a release, and an acquire order a prior
> + * store against a subsequent store?
> + *)
> +
> +{}
> +
> +P0(int *x, int *y)
> +{
> + WRITE_ONCE(*x, 2);
> + smp_wmb();
> + WRITE_ONCE(*y, 1);
> +}
> +
> +P1(int *x, int *y)
> +{
> + int r0;
> +
> + r0 = smp_load_acquire(y);
> + WRITE_ONCE(*x, 1);
> +}
> +
> +exists (x=2 /\ 1:r0=1)
> diff --git a/tools/memory-model/litmus-tests/S+wmbonceonce+poacquireonce.litmus b/tools/memory-model/litmus-tests/S+wmbonceonce+poacquireonce.litmus
> deleted file mode 100644
> index c53350205d282..0000000000000
> --- a/tools/memory-model/litmus-tests/S+wmbonceonce+poacquireonce.litmus
> +++ /dev/null
> @@ -1,27 +0,0 @@
> -C S+wmbonceonce+poacquireonce
> -
> -(*
> - * Result: Never
> - *
> - * Can a smp_wmb(), instead of a release, and an acquire order a prior
> - * store against a subsequent store?
> - *)
> -
> -{}
> -
> -P0(int *x, int *y)
> -{
> - WRITE_ONCE(*x, 2);
> - smp_wmb();
> - WRITE_ONCE(*y, 1);
> -}
> -
> -P1(int *x, int *y)
> -{
> - int r0;
> -
> - r0 = smp_load_acquire(y);
> - WRITE_ONCE(*x, 1);
> -}
> -
> -exists (x=2 /\ 1:r0=1)
> diff --git a/tools/memory-model/litmus-tests/SB+fencembonceonces.litmus b/tools/memory-model/litmus-tests/SB+fencembonceonces.litmus
> new file mode 100644
> index 0000000000000..ed5fff18d2232
> --- /dev/null
> +++ b/tools/memory-model/litmus-tests/SB+fencembonceonces.litmus
> @@ -0,0 +1,32 @@
> +C SB+fencembonceonces
> +
> +(*
> + * Result: Never
> + *
> + * This litmus test demonstrates that full memory barriers suffice to
> + * order the store-buffering pattern, where each process writes to the
> + * variable that the preceding process reads. (Locking and RCU can also
> + * suffice, but not much else.)
> + *)
> +
> +{}
> +
> +P0(int *x, int *y)
> +{
> + int r0;
> +
> + WRITE_ONCE(*x, 1);
> + smp_mb();
> + r0 = READ_ONCE(*y);
> +}
> +
> +P1(int *x, int *y)
> +{
> + int r0;
> +
> + WRITE_ONCE(*y, 1);
> + smp_mb();
> + r0 = READ_ONCE(*x);
> +}
> +
> +exists (0:r0=0 /\ 1:r0=0)
> diff --git a/tools/memory-model/litmus-tests/SB+mbonceonces.litmus b/tools/memory-model/litmus-tests/SB+mbonceonces.litmus
> deleted file mode 100644
> index 74b874ffa8dad..0000000000000
> --- a/tools/memory-model/litmus-tests/SB+mbonceonces.litmus
> +++ /dev/null
> @@ -1,32 +0,0 @@
> -C SB+mbonceonces
> -
> -(*
> - * Result: Never
> - *
> - * This litmus test demonstrates that full memory barriers suffice to
> - * order the store-buffering pattern, where each process writes to the
> - * variable that the preceding process reads. (Locking and RCU can also
> - * suffice, but not much else.)
> - *)
> -
> -{}
> -
> -P0(int *x, int *y)
> -{
> - int r0;
> -
> - WRITE_ONCE(*x, 1);
> - smp_mb();
> - r0 = READ_ONCE(*y);
> -}
> -
> -P1(int *x, int *y)
> -{
> - int r0;
> -
> - WRITE_ONCE(*y, 1);
> - smp_mb();
> - r0 = READ_ONCE(*x);
> -}
> -
> -exists (0:r0=0 /\ 1:r0=0)
> diff --git a/tools/memory-model/litmus-tests/WRC+pooncerelease+fencermbonceonce+Once.litmus b/tools/memory-model/litmus-tests/WRC+pooncerelease+fencermbonceonce+Once.litmus
> new file mode 100644
> index 0000000000000..e9947250d7de6
> --- /dev/null
> +++ b/tools/memory-model/litmus-tests/WRC+pooncerelease+fencermbonceonce+Once.litmus
> @@ -0,0 +1,38 @@
> +C WRC+pooncerelease+fencermbonceonce+Once
> +
> +(*
> + * Result: Never
> + *
> + * This litmus test is an extension of the message-passing pattern, where
> + * the first write is moved to a separate process. Because it features
> + * a release and a read memory barrier, it should be forbidden. More
> + * specifically, this litmus test is forbidden because smp_store_release()
> + * is A-cumulative in LKMM.
> + *)
> +
> +{}
> +
> +P0(int *x)
> +{
> + WRITE_ONCE(*x, 1);
> +}
> +
> +P1(int *x, int *y)
> +{
> + int r0;
> +
> + r0 = READ_ONCE(*x);
> + smp_store_release(y, 1);
> +}
> +
> +P2(int *x, int *y)
> +{
> + int r0;
> + int r1;
> +
> + r0 = READ_ONCE(*y);
> + smp_rmb();
> + r1 = READ_ONCE(*x);
> +}
> +
> +exists (1:r0=1 /\ 2:r0=1 /\ 2:r1=0)
> diff --git a/tools/memory-model/litmus-tests/WRC+pooncerelease+rmbonceonce+Once.litmus b/tools/memory-model/litmus-tests/WRC+pooncerelease+rmbonceonce+Once.litmus
> deleted file mode 100644
> index ad3448b941e68..0000000000000
> --- a/tools/memory-model/litmus-tests/WRC+pooncerelease+rmbonceonce+Once.litmus
> +++ /dev/null
> @@ -1,38 +0,0 @@
> -C WRC+pooncerelease+rmbonceonce+Once
> -
> -(*
> - * Result: Never
> - *
> - * This litmus test is an extension of the message-passing pattern, where
> - * the first write is moved to a separate process. Because it features
> - * a release and a read memory barrier, it should be forbidden. More
> - * specifically, this litmus test is forbidden because smp_store_release()
> - * is A-cumulative in LKMM.
> - *)
> -
> -{}
> -
> -P0(int *x)
> -{
> - WRITE_ONCE(*x, 1);
> -}
> -
> -P1(int *x, int *y)
> -{
> - int r0;
> -
> - r0 = READ_ONCE(*x);
> - smp_store_release(y, 1);
> -}
> -
> -P2(int *x, int *y)
> -{
> - int r0;
> - int r1;
> -
> - r0 = READ_ONCE(*y);
> - smp_rmb();
> - r1 = READ_ONCE(*x);
> -}
> -
> -exists (1:r0=1 /\ 2:r0=1 /\ 2:r1=0)
> diff --git a/tools/memory-model/litmus-tests/Z6.0+pooncerelease+poacquirerelease+fencembonceonce.litmus b/tools/memory-model/litmus-tests/Z6.0+pooncerelease+poacquirerelease+fencembonceonce.litmus
> new file mode 100644
> index 0000000000000..88e70b87a683e
> --- /dev/null
> +++ b/tools/memory-model/litmus-tests/Z6.0+pooncerelease+poacquirerelease+fencembonceonce.litmus
> @@ -0,0 +1,42 @@
> +C Z6.0+pooncerelease+poacquirerelease+fencembonceonce
> +
> +(*
> + * Result: Sometimes
> + *
> + * This litmus test shows that a release-acquire chain, while sufficient
> + * when there is but one non-reads-from (AKA non-rf) link, does not suffice
> + * if there is more than one. Of the three processes, only P1() reads from
> + * P0's write, which means that there are two non-rf links: P1() to P2()
> + * is a write-to-write link (AKA a "coherence" or just "co" link) and P2()
> + * to P0() is a read-to-write link (AKA a "from-reads" or just "fr" link).
> + * When there are two or more non-rf links, you typically will need one
> + * full barrier for each non-rf link. (Exceptions include some cases
> + * involving locking.)
> + *)
> +
> +{}
> +
> +P0(int *x, int *y)
> +{
> + WRITE_ONCE(*x, 1);
> + smp_store_release(y, 1);
> +}
> +
> +P1(int *y, int *z)
> +{
> + int r0;
> +
> + r0 = smp_load_acquire(y);
> + smp_store_release(z, 1);
> +}
> +
> +P2(int *x, int *z)
> +{
> + int r1;
> +
> + WRITE_ONCE(*z, 2);
> + smp_mb();
> + r1 = READ_ONCE(*x);
> +}
> +
> +exists (1:r0=1 /\ z=2 /\ 2:r1=0)
> diff --git a/tools/memory-model/litmus-tests/Z6.0+pooncerelease+poacquirerelease+mbonceonce.litmus b/tools/memory-model/litmus-tests/Z6.0+pooncerelease+poacquirerelease+mbonceonce.litmus
> deleted file mode 100644
> index a20fc3fafb536..0000000000000
> --- a/tools/memory-model/litmus-tests/Z6.0+pooncerelease+poacquirerelease+mbonceonce.litmus
> +++ /dev/null
> @@ -1,42 +0,0 @@
> -C Z6.0+pooncerelease+poacquirerelease+mbonceonce
> -
> -(*
> - * Result: Sometimes
> - *
> - * This litmus test shows that a release-acquire chain, while sufficient
> - * when there is but one non-reads-from (AKA non-rf) link, does not suffice
> - * if there is more than one. Of the three processes, only P1() reads from
> - * P0's write, which means that there are two non-rf links: P1() to P2()
> - * is a write-to-write link (AKA a "coherence" or just "co" link) and P2()
> - * to P0() is a read-to-write link (AKA a "from-reads" or just "fr" link).
> - * When there are two or more non-rf links, you typically will need one
> - * full barrier for each non-rf link. (Exceptions include some cases
> - * involving locking.)
> - *)
> -
> -{}
> -
> -P0(int *x, int *y)
> -{
> - WRITE_ONCE(*x, 1);
> - smp_store_release(y, 1);
> -}
> -
> -P1(int *y, int *z)
> -{
> - int r0;
> -
> - r0 = smp_load_acquire(y);
> - smp_store_release(z, 1);
> -}
> -
> -P2(int *x, int *z)
> -{
> - int r1;
> -
> - WRITE_ONCE(*z, 2);
> - smp_mb();
> - r1 = READ_ONCE(*x);
> -}
> -
> -exists (1:r0=1 /\ z=2 /\ 2:r1=0)
> --
> 2.7.4
>
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