linux_dsm_epyc7002/tools/memory-model/litmus-tests/LB+fencembonceonce+ctrlonceonce.litmus
Andrea Parri 71b7ff5ebc tools/memory-model: Rename litmus tests to comply to norm7
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>
2018-07-17 09:30:36 +02:00

35 lines
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Plaintext

C LB+fencembonceonce+ctrlonceonce
(*
* Result: Never
*
* This litmus test demonstrates that lightweight ordering suffices for
* the load-buffering pattern, in other words, preventing all processes
* reading from the preceding process's write. In this example, the
* combination of a control dependency and a full memory barrier are enough
* to do the trick. (But the full memory barrier could be replaced with
* another control dependency and order would still be maintained.)
*)
{}
P0(int *x, int *y)
{
int r0;
r0 = READ_ONCE(*x);
if (r0)
WRITE_ONCE(*y, 1);
}
P1(int *x, int *y)
{
int r0;
r0 = READ_ONCE(*y);
smp_mb();
WRITE_ONCE(*x, 1);
}
exists (0:r0=1 /\ 1:r0=1)