43 lines
723 B
Plaintext
43 lines
723 B
Plaintext
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C Z6.0+pooncelock+poonceLock+pombonce
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(*
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* Result: Never
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*
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* This litmus test demonstrates how smp_mb__after_spinlock() may be
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* used to ensure that accesses in different critical sections for a
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* given lock running on different CPUs are nevertheless seen in order
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* by CPUs not holding that lock.
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*)
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{}
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P0(int *x, int *y, spinlock_t *mylock)
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{
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spin_lock(mylock);
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WRITE_ONCE(*x, 1);
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WRITE_ONCE(*y, 1);
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spin_unlock(mylock);
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}
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P1(int *y, int *z, spinlock_t *mylock)
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{
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int r0;
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spin_lock(mylock);
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smp_mb__after_spinlock();
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r0 = READ_ONCE(*y);
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WRITE_ONCE(*z, 1);
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spin_unlock(mylock);
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}
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P2(int *x, int *z)
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{
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int r1;
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WRITE_ONCE(*z, 2);
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smp_mb();
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r1 = READ_ONCE(*x);
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}
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exists (1:r0=1 /\ z=2 /\ 2:r1=0)
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