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5c587f9b9c
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>
36 lines
825 B
Plaintext
36 lines
825 B
Plaintext
C MP+polocks
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(*
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* Result: Never
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*
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* This litmus test demonstrates how lock acquisitions and releases can
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* stand in for smp_load_acquire() and smp_store_release(), respectively.
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* In other words, when holding a given lock (or indeed after releasing a
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* given lock), a CPU is not only guaranteed to see the accesses that other
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* CPUs made while previously holding that lock, it is also guaranteed
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* to see all prior accesses by those other CPUs.
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*)
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{}
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P0(int *buf, int *flag, spinlock_t *mylock) // Producer
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{
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WRITE_ONCE(*buf, 1);
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spin_lock(mylock);
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WRITE_ONCE(*flag, 1);
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spin_unlock(mylock);
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}
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P1(int *buf, int *flag, spinlock_t *mylock) // Consumer
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{
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int r0;
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int r1;
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spin_lock(mylock);
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r0 = READ_ONCE(*flag);
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spin_unlock(mylock);
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r1 = READ_ONCE(*buf);
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}
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exists (1:r0=1 /\ 1:r1=0) (* Bad outcome. *)
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