1This directory contains the following litmus tests:
  2
  3CoRR+poonceonce+Once.litmus
  4	Test of read-read coherence, that is, whether or not two
  5	successive reads from the same variable are ordered.
  6
  7CoRW+poonceonce+Once.litmus
  8	Test of read-write coherence, that is, whether or not a read
  9	from a given variable followed by a write to that same variable
 10	are ordered.
 11
 12CoWR+poonceonce+Once.litmus
 13	Test of write-read coherence, that is, whether or not a write
 14	to a given variable followed by a read from that same variable
 15	are ordered.
 16
 17CoWW+poonceonce.litmus
 18	Test of write-write coherence, that is, whether or not two
 19	successive writes to the same variable are ordered.
 20
 21IRIW+mbonceonces+OnceOnce.litmus
 22	Test of independent reads from independent writes with smp_mb()
 23	between each pairs of reads.  In other words, is smp_mb()
 24	sufficient to cause two different reading processes to agree on
 25	the order of a pair of writes, where each write is to a different
 26	variable by a different process?
 27
 28IRIW+poonceonces+OnceOnce.litmus
 29	Test of independent reads from independent writes with nothing
 30	between each pairs of reads.  In other words, is anything at all
 31	needed to cause two different reading processes to agree on the
 32	order of a pair of writes, where each write is to a different
 33	variable by a different process?
 34
 35ISA2+pooncelock+pooncelock+pombonce.litmus
 36	Tests whether the ordering provided by a lock-protected S
 37	litmus test is visible to an external process whose accesses are
 38	separated by smp_mb().	This addition of an external process to
 39	S is otherwise known as ISA2.
 40
 41ISA2+poonceonces.litmus
 42	As below, but with store-release replaced with WRITE_ONCE()
 43	and load-acquire replaced with READ_ONCE().
 44
 45ISA2+pooncerelease+poacquirerelease+poacquireonce.litmus
 46	Can a release-acquire chain order a prior store against
 47	a later load?
 48
 49LB+ctrlonceonce+mbonceonce.litmus
 50	Does a control dependency and an smp_mb() suffice for the
 51	load-buffering litmus test, where each process reads from one
 52	of two variables then writes to the other?
 53
 54LB+poacquireonce+pooncerelease.litmus
 55	Does a release-acquire pair suffice for the load-buffering
 56	litmus test, where each process reads from one of two variables then
 57	writes to the other?
 58
 59LB+poonceonces.litmus
 60	As above, but with store-release replaced with WRITE_ONCE()
 61	and load-acquire replaced with READ_ONCE().
 62
 63MP+onceassign+derefonce.litmus
 64	As below, but with rcu_assign_pointer() and an rcu_dereference().
 65
 66MP+polocks.litmus
 67	As below, but with the second access of the writer process
 68	and the first access of reader process protected by a lock.
 69
 70MP+poonceonces.litmus
 71	As below, but without the smp_rmb() and smp_wmb().
 72
 73MP+pooncerelease+poacquireonce.litmus
 74	As below, but with a release-acquire chain.
 75
 76MP+porevlocks.litmus
 77	As below, but with the first access of the writer process
 78	and the second access of reader process protected by a lock.
 79
 80MP+wmbonceonce+rmbonceonce.litmus
 81	Does a smp_wmb() (between the stores) and an smp_rmb() (between
 82	the loads) suffice for the message-passing litmus test, where one
 83	process writes data and then a flag, and the other process reads
 84	the flag and then the data.  (This is similar to the ISA2 tests,
 85	but with two processes instead of three.)
 86
 87R+mbonceonces.litmus
 88	This is the fully ordered (via smp_mb()) version of one of
 89	the classic counterintuitive litmus tests that illustrates the
 90	effects of store propagation delays.
 91
 92R+poonceonces.litmus
 93	As above, but without the smp_mb() invocations.
 94
 95SB+mbonceonces.litmus
 96	This is the fully ordered (again, via smp_mb() version of store
 97	buffering, which forms the core of Dekker's mutual-exclusion
 98	algorithm.
 99
100SB+poonceonces.litmus
101	As above, but without the smp_mb() invocations.
102
103S+poonceonces.litmus
104	As below, but without the smp_wmb() and acquire load.
105
106S+wmbonceonce+poacquireonce.litmus
107	Can a smp_wmb(), instead of a release, and an acquire order
108	a prior store against a subsequent store?
109
110WRC+poonceonces+Once.litmus
111WRC+pooncerelease+rmbonceonce+Once.litmus
112	These two are members of an extension of the MP litmus-test class
113	in which the first write is moved to a separate process.
114
115Z6.0+pooncelock+pooncelock+pombonce.litmus
116	Is the ordering provided by a spin_unlock() and a subsequent
117	spin_lock() sufficient to make ordering apparent to accesses
118	by a process not holding the lock?
119
120Z6.0+pooncelock+poonceLock+pombonce.litmus
121	As above, but with smp_mb__after_spinlock() immediately
122	following the spin_lock().
123
124Z6.0+pooncerelease+poacquirerelease+mbonceonce.litmus
125	Is the ordering provided by a release-acquire chain sufficient
126	to make ordering apparent to accesses by a process that does
127	not participate in that release-acquire chain?
128
129A great many more litmus tests are available here:
130
131	https://github.com/paulmckrcu/litmus