[mirror_ubuntu-jammy-kernel.git] / Documentation / litmus-tests / README

============
LITMUS TESTS
============

Each subdirectory contains litmus tests that are typical to describe the
semantics of respective kernel APIs.
For more information about how to "run" a litmus test or how to generate
a kernel test module based on a litmus test, please see
tools/memory-model/README.


atomic (/atomic derectory)
--------------------------

Atomic-RMW+mb__after_atomic-is-stronger-than-acquire.litmus
    Test that an atomic RMW followed by a smp_mb__after_atomic() is
    stronger than a normal acquire: both the read and write parts of
    the RMW are ordered before the subsequential memory accesses.

Atomic-RMW-ops-are-atomic-WRT-atomic_set.litmus
    Test that atomic_set() cannot break the atomicity of atomic RMWs.
    NOTE: Require herd7 7.56 or later which supports "(void)expr".


RCU (/rcu directory)
--------------------

MP+onceassign+derefonce.litmus (under tools/memory-model/litmus-tests/)
    Demonstrates the use of rcu_assign_pointer() and rcu_dereference() to
    ensure that an RCU reader will not see pre-initialization garbage.

RCU+sync+read.litmus
RCU+sync+free.litmus
    Both the above litmus tests demonstrate the RCU grace period guarantee
    that an RCU read-side critical section can never span a grace period.
Commit	Line	Data
a591890c JFG	1	============
	2	LITMUS TESTS
	3	============
	4
cdaac9d6 AY	5	Each subdirectory contains litmus tests that are typical to describe the
	6	semantics of respective kernel APIs.
	7	For more information about how to "run" a litmus test or how to generate
	8	a kernel test module based on a litmus test, please see
	9	tools/memory-model/README.
	10
	11
	12	atomic (/atomic derectory)
	13	--------------------------
	14
	15	Atomic-RMW+mb__after_atomic-is-stronger-than-acquire.litmus
	16	Test that an atomic RMW followed by a smp_mb__after_atomic() is
	17	stronger than a normal acquire: both the read and write parts of
	18	the RMW are ordered before the subsequential memory accesses.
	19
	20	Atomic-RMW-ops-are-atomic-WRT-atomic_set.litmus
	21	Test that atomic_set() cannot break the atomicity of atomic RMWs.
5ef0a07a	22	NOTE: Require herd7 7.56 or later which supports "(void)expr".
cdaac9d6 AY	23
cdaac9d6 AY	24
a591890c JFG	25	RCU (/rcu directory)
	26	--------------------
	27
c425fb5f JFG	28	MP+onceassign+derefonce.litmus (under tools/memory-model/litmus-tests/)
	29	Demonstrates the use of rcu_assign_pointer() and rcu_dereference() to
	30	ensure that an RCU reader will not see pre-initialization garbage.
	31
a591890c JFG	32	RCU+sync+read.litmus
	33	RCU+sync+free.litmus
	34	Both the above litmus tests demonstrate the RCU grace period guarantee
	35	that an RCU read-side critical section can never span a grace period.