mirror of https://gitee.com/openkylin/linux.git
42 lines
652 B
Plaintext
42 lines
652 B
Plaintext
C ISA2+pooncelock+pooncelock+pombonce.litmus
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(*
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* Result: Sometimes
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*
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* This test shows that the ordering provided by a lock-protected S
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* litmus test (P0() and P1()) are not visible to external process P2().
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* This is likely to change soon.
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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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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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int r2;
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r2 = READ_ONCE(*z);
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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 /\ 2:r2=1 /\ 2:r1=0)
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