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+polockmbonce+poacquiresilsil.litmus
67	Protect the access with a lock and an smp_mb__after_spinlock()
68	in one process, and use an acquire load followed by a pair of
69	spin_is_locked() calls in the other process.
70
71MP+polockonce+poacquiresilsil.litmus
72	Protect the access with a lock in one process, and use an
73	acquire load followed by a pair of spin_is_locked() calls
74	in the other process.
75
76MP+polocks.litmus
77	As below, but with the second access of the writer process
78	and the first access of reader process protected by a lock.
79
80MP+poonceonces.litmus
81	As below, but without the smp_rmb() and smp_wmb().
82
83MP+pooncerelease+poacquireonce.litmus
84	As below, but with a release-acquire chain.
85
86MP+porevlocks.litmus
87	As below, but with the first access of the writer process
88	and the second access of reader process protected by a lock.
89
90MP+wmbonceonce+rmbonceonce.litmus
91	Does a smp_wmb() (between the stores) and an smp_rmb() (between
92	the loads) suffice for the message-passing litmus test, where one
93	process writes data and then a flag, and the other process reads
94	the flag and then the data.  (This is similar to the ISA2 tests,
95	but with two processes instead of three.)
96
97R+mbonceonces.litmus
98	This is the fully ordered (via smp_mb()) version of one of
99	the classic counterintuitive litmus tests that illustrates the
100	effects of store propagation delays.
101
102R+poonceonces.litmus
103	As above, but without the smp_mb() invocations.
104
105SB+mbonceonces.litmus
106	This is the fully ordered (again, via smp_mb() version of store
107	buffering, which forms the core of Dekker's mutual-exclusion
108	algorithm.
109
110SB+poonceonces.litmus
111	As above, but without the smp_mb() invocations.
112
113S+poonceonces.litmus
114	As below, but without the smp_wmb() and acquire load.
115
116S+wmbonceonce+poacquireonce.litmus
117	Can a smp_wmb(), instead of a release, and an acquire order
118	a prior store against a subsequent store?
119
120WRC+poonceonces+Once.litmus
121WRC+pooncerelease+rmbonceonce+Once.litmus
122	These two are members of an extension of the MP litmus-test class
123	in which the first write is moved to a separate process.
124
125Z6.0+pooncelock+pooncelock+pombonce.litmus
126	Is the ordering provided by a spin_unlock() and a subsequent
127	spin_lock() sufficient to make ordering apparent to accesses
128	by a process not holding the lock?
129
130Z6.0+pooncelock+poonceLock+pombonce.litmus
131	As above, but with smp_mb__after_spinlock() immediately
132	following the spin_lock().
133
134Z6.0+pooncerelease+poacquirerelease+mbonceonce.litmus
135	Is the ordering provided by a release-acquire chain sufficient
136	to make ordering apparent to accesses by a process that does
137	not participate in that release-acquire chain?
138
139A great many more litmus tests are available here:
140
141	https://github.com/paulmckrcu/litmus
142