[RFC v2 2/3] tools/memory-model: doc: Describe the requirement of the litmus-tests directory

[Boqun Feng <boqun.feng@gmail.com>]

It's better that we have some "standard" about which test should be put
in the litmus-tests directory because it helps future contributors
understand whether they should work on litmus-tests in kernel or Paul's
GitHub repo. Therefore explain a little bit on what a "representative"
litmus test is.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
---
 tools/memory-model/README | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tools/memory-model/README b/tools/memory-model/README
index 9a84c45504ab..9edd402704c4 100644
--- a/tools/memory-model/README
+++ b/tools/memory-model/README
@@ -195,6 +195,18 @@ litmus-tests
 	are listed in litmus-tests/README.  A great deal more litmus
 	tests are available at https://github.com/paulmckrcu/litmus.
 
+	By "representative", it means the one in the litmus-tests
+	directory is:
+
+		1) simple, the number of threads should be relatively
+		   small and each thread function should be relatively
+		   simple.
+		2) orthogonal, there should be no two litmus tests
+		   describing the same aspect of the memory model.
+		3) textbook, developers can easily copy-paste-modify
+		   the litmus tests to use the patterns on their own
+		   code.
+
 lock.cat
 	Provides a front-end analysis of lock acquisition and release,
 	for example, associating a lock acquisition with the preceding
-- 
2.33.0