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diff --git a/tools/memory-model/litmus-tests/README b/tools/memory-model/litmus-tests/README new file mode 100644 index 000000000..4581ec2d3 --- /dev/null +++ b/tools/memory-model/litmus-tests/README @@ -0,0 +1,153 @@ +This directory contains the following litmus tests: + +CoRR+poonceonce+Once.litmus + Test of read-read coherence, that is, whether or not two + successive reads from the same variable are ordered. + +CoRW+poonceonce+Once.litmus + Test of read-write coherence, that is, whether or not a read + from a given variable followed by a write to that same variable + are ordered. + +CoWR+poonceonce+Once.litmus + Test of write-read coherence, that is, whether or not a write + to a given variable followed by a read from that same variable + are ordered. + +CoWW+poonceonce.litmus + Test of write-write coherence, that is, whether or not two + successive writes to the same variable are ordered. + +IRIW+fencembonceonces+OnceOnce.litmus + Test of independent reads from independent writes with smp_mb() + between each pairs of reads. In other words, is smp_mb() + sufficient 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? This litmus test is forbidden + by LKMM's propagation rule. + +IRIW+poonceonces+OnceOnce.litmus + 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? + +ISA2+pooncelock+pooncelock+pombonce.litmus + Tests whether the ordering provided by a lock-protected S + litmus test is visible to an external process whose accesses are + separated by smp_mb(). This addition of an external process to + S is otherwise known as ISA2. + +ISA2+poonceonces.litmus + As below, but with store-release replaced with WRITE_ONCE() + and load-acquire replaced with READ_ONCE(). + +ISA2+pooncerelease+poacquirerelease+poacquireonce.litmus + Can a release-acquire chain order a prior store against + a later load? + +LB+fencembonceonce+ctrlonceonce.litmus + Does a control dependency and an smp_mb() suffice for the + load-buffering litmus test, where each process reads from one + of two variables then writes to the other? + +LB+poacquireonce+pooncerelease.litmus + Does a release-acquire pair suffice for the load-buffering + litmus test, where each process reads from one of two variables then + writes to the other? + +LB+poonceonces.litmus + As above, but with store-release replaced with WRITE_ONCE() + and load-acquire replaced with READ_ONCE(). + +MP+onceassign+derefonce.litmus + As below, but with rcu_assign_pointer() and an rcu_dereference(). + +MP+polockmbonce+poacquiresilsil.litmus + Protect the access with a lock and an smp_mb__after_spinlock() + in one process, and use an acquire load followed by a pair of + spin_is_locked() calls in the other process. + +MP+polockonce+poacquiresilsil.litmus + Protect the access with a lock in one process, and use an + acquire load followed by a pair of spin_is_locked() calls + in the other process. + +MP+polocks.litmus + As below, but with the second access of the writer process + and the first access of reader process protected by a lock. + +MP+poonceonces.litmus + As below, but without the smp_rmb() and smp_wmb(). + +MP+pooncerelease+poacquireonce.litmus + As below, but with a release-acquire chain. + +MP+porevlocks.litmus + As below, but with the first access of the writer process + and the second access of reader process protected by a lock. + +MP+fencewmbonceonce+fencermbonceonce.litmus + Does a smp_wmb() (between the stores) and an smp_rmb() (between + the loads) suffice for the message-passing litmus test, where one + process writes data and then a flag, and the other process reads + the flag and then the data. (This is similar to the ISA2 tests, + but with two processes instead of three.) + +R+fencembonceonces.litmus + This is the fully ordered (via smp_mb()) version of one of + the classic counterintuitive litmus tests that illustrates the + effects of store propagation delays. + +R+poonceonces.litmus + As above, but without the smp_mb() invocations. + +SB+fencembonceonces.litmus + This is the fully ordered (again, via smp_mb() version of store + buffering, which forms the core of Dekker's mutual-exclusion + algorithm. + +SB+poonceonces.litmus + As above, but without the smp_mb() invocations. + +SB+rfionceonce-poonceonces.litmus + This litmus test demonstrates that LKMM is not fully multicopy + atomic. (Neither is it other multicopy atomic.) This litmus test + also demonstrates the "locations" debugging aid, which designates + additional registers and locations to be printed out in the dump + of final states in the herd7 output. Without the "locations" + statement, only those registers and locations mentioned in the + "exists" clause will be printed. + +S+poonceonces.litmus + As below, but without the smp_wmb() and acquire load. + +S+fencewmbonceonce+poacquireonce.litmus + Can a smp_wmb(), instead of a release, and an acquire order + a prior store against a subsequent store? + +WRC+poonceonces+Once.litmus +WRC+pooncerelease+fencermbonceonce+Once.litmus + These two are members of an extension of the MP litmus-test + class in which the first write is moved to a separate process. + The second is forbidden because smp_store_release() is + A-cumulative in LKMM. + +Z6.0+pooncelock+pooncelock+pombonce.litmus + Is the ordering provided by a spin_unlock() and a subsequent + spin_lock() sufficient to make ordering apparent to accesses + by a process not holding the lock? + +Z6.0+pooncelock+poonceLock+pombonce.litmus + As above, but with smp_mb__after_spinlock() immediately + following the spin_lock(). + +Z6.0+pooncerelease+poacquirerelease+fencembonceonce.litmus + Is the ordering provided by a release-acquire chain sufficient + to make ordering apparent to accesses by a process that does + not participate in that release-acquire chain? + +A great many more litmus tests are available here: + + https://github.com/paulmckrcu/litmus |