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-rw-r--r--tools/memory-model/litmus-tests/MP+polocks.litmus35
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diff --git a/tools/memory-model/litmus-tests/MP+polocks.litmus b/tools/memory-model/litmus-tests/MP+polocks.litmus
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+++ b/tools/memory-model/litmus-tests/MP+polocks.litmus
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+C MP+polocks
+
+(*
+ * Result: Never
+ *
+ * This litmus test demonstrates how lock acquisitions and releases can
+ * stand in for smp_load_acquire() and smp_store_release(), respectively.
+ * In other words, when holding a given lock (or indeed after releasing a
+ * given lock), a CPU is not only guaranteed to see the accesses that other
+ * CPUs made while previously holding that lock, it is also guaranteed
+ * to see all prior accesses by those other CPUs.
+ *)
+
+{}
+
+P0(int *x, int *y, spinlock_t *mylock)
+{
+ WRITE_ONCE(*x, 1);
+ spin_lock(mylock);
+ WRITE_ONCE(*y, 1);
+ spin_unlock(mylock);
+}
+
+P1(int *x, int *y, spinlock_t *mylock)
+{
+ int r0;
+ int r1;
+
+ spin_lock(mylock);
+ r0 = READ_ONCE(*y);
+ spin_unlock(mylock);
+ r1 = READ_ONCE(*x);
+}
+
+exists (1:r0=1 /\ 1:r1=0)