145 lines
		
	
	
		
			5.2 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			145 lines
		
	
	
		
			5.2 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| 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+mbonceonces+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+ctrlonceonce+mbonceonce.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+wmbonceonce+rmbonceonce.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+mbonceonces.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+mbonceonces.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.
 | |
| 
 | |
| S+poonceonces.litmus
 | |
| 	As below, but without the smp_wmb() and acquire load.
 | |
| 
 | |
| S+wmbonceonce+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+rmbonceonce+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+mbonceonce.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
 |