linux/tools/memory-model/litmus-tests/IRIW+poonceonces+OnceOnce.litmus
Paul E. McKenney 8f32543b61 EXP litmus_tests: Add comments explaining tests' purposes
This commit adds comments to the litmus tests summarizing what these
tests are intended to demonstrate.

[ paulmck: Apply Andrea's and Alan's feedback. ]
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akiyks@gmail.com
Cc: boqun.feng@gmail.com
Cc: dhowells@redhat.com
Cc: j.alglave@ucl.ac.uk
Cc: linux-arch@vger.kernel.org
Cc: luc.maranget@inria.fr
Cc: nborisov@suse.com
Cc: npiggin@gmail.com
Cc: parri.andrea@gmail.com
Cc: stern@rowland.harvard.edu
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1519169112-20593-4-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-21 09:58:13 +01:00

44 lines
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Plaintext

C IRIW+poonceonces+OnceOnce
(*
* Result: Sometimes
*
* Test of independent reads from independent writes with nothing
* between each pairs of reads. In other words, is anything at all
* needed to cause two different reading processes to agree on the order
* of a pair of writes, where each write is to a different variable by a
* different process?
*)
{}
P0(int *x)
{
WRITE_ONCE(*x, 1);
}
P1(int *x, int *y)
{
int r0;
int r1;
r0 = READ_ONCE(*x);
r1 = READ_ONCE(*y);
}
P2(int *y)
{
WRITE_ONCE(*y, 1);
}
P3(int *x, int *y)
{
int r0;
int r1;
r0 = READ_ONCE(*y);
r1 = READ_ONCE(*x);
}
exists (1:r0=1 /\ 1:r1=0 /\ 3:r0=1 /\ 3:r1=0)