linux/tools/memory-model/litmus-tests/SB+rfionceonce-poonceonces.litmus
Paul E. McKenney b464818978 tools/memory-model: Add litmus test for full multicopy atomicity
This commit adds a litmus test suggested by Alan Stern that is forbidden
on fully multicopy atomic systems, but allowed on other-multicopy and
on non-multicopy atomic systems.  For reference, s390 is fully multicopy
atomic, x86 and ARMv8 are other-multicopy atomic, and ARMv7 and powerpc
are non-multicopy atomic.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.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: npiggin@gmail.com
Cc: parri.andrea@gmail.com
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/20180716180605.16115-1-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17 09:29:29 +02:00

33 lines
452 B
Plaintext

C SB+rfionceonce-poonceonces
(*
* Result: Sometimes
*
* This litmus test demonstrates that LKMM is not fully multicopy atomic.
*)
{}
P0(int *x, int *y)
{
int r1;
int r2;
WRITE_ONCE(*x, 1);
r1 = READ_ONCE(*x);
r2 = READ_ONCE(*y);
}
P1(int *x, int *y)
{
int r3;
int r4;
WRITE_ONCE(*y, 1);
r3 = READ_ONCE(*y);
r4 = READ_ONCE(*x);
}
locations [0:r1; 1:r3; x; y] (* Debug aid: Print things not in "exists". *)
exists (0:r2=0 /\ 1:r4=0)