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linux-next/tools/memory-model/litmus-tests/Z6.0+pooncelock+poonceLock+pombonce.litmus
Akira Yokosawa 5c587f9b9c tools/memory-model: Remove redundant initialization in litmus tests
This is a revert of commit 1947bfcf81 ("tools/memory-model: Add types
to litmus tests") with conflict resolutions.

klitmus7 [1] is aware of default types of "int" and "int*".
It accepts litmus tests for herd7 without extra type info unless
non-"int" variables are referenced by an "exists", "locations",
or "filter" directive.

[1]: Tested with klitmus7 versions 7.49 or later.

Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-01-04 14:40:49 -08:00

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C Z6.0+pooncelock+poonceLock+pombonce
(*
* Result: Never
*
* This litmus test demonstrates how smp_mb__after_spinlock() may be
* used to ensure that accesses in different critical sections for a
* given lock running on different CPUs are nevertheless seen in order
* by CPUs not holding that lock.
*)
{}
P0(int *x, int *y, spinlock_t *mylock)
{
spin_lock(mylock);
WRITE_ONCE(*x, 1);
WRITE_ONCE(*y, 1);
spin_unlock(mylock);
}
P1(int *y, int *z, spinlock_t *mylock)
{
int r0;
spin_lock(mylock);
smp_mb__after_spinlock();
r0 = READ_ONCE(*y);
WRITE_ONCE(*z, 1);
spin_unlock(mylock);
}
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)