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71b7ff5ebc
norm7 produces the 'normalized' name of a litmus test, when the test can be generated from a single cycle that passes through each process exactly once. The commit renames such tests in order to comply to the naming scheme implemented by this tool. Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: Akira Yokosawa <akiyks@gmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Jade Alglave <j.alglave@ucl.ac.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luc Maranget <luc.maranget@inria.fr> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arch@vger.kernel.org Cc: parri.andrea@gmail.com Link: http://lkml.kernel.org/r/20180716180605.16115-14-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
35 lines
694 B
Plaintext
35 lines
694 B
Plaintext
C LB+fencembonceonce+ctrlonceonce
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(*
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* Result: Never
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*
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* This litmus test demonstrates that lightweight ordering suffices for
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* the load-buffering pattern, in other words, preventing all processes
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* reading from the preceding process's write. In this example, the
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* combination of a control dependency and a full memory barrier are enough
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* to do the trick. (But the full memory barrier could be replaced with
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* another control dependency and order would still be maintained.)
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*)
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{}
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P0(int *x, int *y)
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{
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int r0;
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r0 = READ_ONCE(*x);
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if (r0)
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WRITE_ONCE(*y, 1);
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}
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P1(int *x, int *y)
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{
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int r0;
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r0 = READ_ONCE(*y);
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smp_mb();
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WRITE_ONCE(*x, 1);
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}
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exists (0:r0=1 /\ 1:r0=1)
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