summaryrefslogtreecommitdiffstats
path: root/tools/memory-model/Documentation/cheatsheet.txt
diff options
context:
space:
mode:
Diffstat (limited to 'tools/memory-model/Documentation/cheatsheet.txt')
-rw-r--r--tools/memory-model/Documentation/cheatsheet.txt35
1 files changed, 35 insertions, 0 deletions
diff --git a/tools/memory-model/Documentation/cheatsheet.txt b/tools/memory-model/Documentation/cheatsheet.txt
new file mode 100644
index 000000000..99d00870b
--- /dev/null
+++ b/tools/memory-model/Documentation/cheatsheet.txt
@@ -0,0 +1,35 @@
+ Prior Operation Subsequent Operation
+ --------------- ---------------------------
+ C Self R W RMW Self R W DR DW RMW SV
+ -- ---- - - --- ---- - - -- -- --- --
+
+Relaxed store Y Y
+Relaxed load Y Y Y Y
+Relaxed RMW operation Y Y Y Y
+rcu_dereference() Y Y Y Y
+Successful *_acquire() R Y Y Y Y Y Y
+Successful *_release() C Y Y Y W Y
+smp_rmb() Y R Y Y R
+smp_wmb() Y W Y Y W
+smp_mb() & synchronize_rcu() CP Y Y Y Y Y Y Y Y
+Successful full non-void RMW CP Y Y Y Y Y Y Y Y Y Y Y
+smp_mb__before_atomic() CP Y Y Y a a a a Y
+smp_mb__after_atomic() CP a a Y Y Y Y Y Y
+
+
+Key: Relaxed: A relaxed operation is either READ_ONCE(), WRITE_ONCE(),
+ a *_relaxed() RMW operation, an unsuccessful RMW
+ operation, a non-value-returning RMW operation such
+ as atomic_inc(), or one of the atomic*_read() and
+ atomic*_set() family of operations.
+ C: Ordering is cumulative
+ P: Ordering propagates
+ R: Read, for example, READ_ONCE(), or read portion of RMW
+ W: Write, for example, WRITE_ONCE(), or write portion of RMW
+ Y: Provides ordering
+ a: Provides ordering given intervening RMW atomic operation
+ DR: Dependent read (address dependency)
+ DW: Dependent write (address, data, or control dependency)
+ RMW: Atomic read-modify-write operation
+ SELF: Orders self, as opposed to accesses before and/or after
+ SV: Orders later accesses to the same variable