[tip: locking/core] tools/memory-model: Expand the cheatsheet.txt notion of relaxed
From: tip-bot2 for Paul E. McKenney
Date: Fri Oct 09 2020 - 03:58:48 EST
The following commit has been merged into the locking/core branch of tip:
Commit-ID: 0ce0c78eff7d22c8a261de6c4305a5abb638c200
Gitweb: https://git.kernel.org/tip/0ce0c78eff7d22c8a261de6c4305a5abb638c200
Author: Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate: Tue, 04 Aug 2020 11:35:56 -07:00
Committer: Paul E. McKenney <paulmck@xxxxxxxxxx>
CommitterDate: Fri, 04 Sep 2020 11:58:15 -07:00
tools/memory-model: Expand the cheatsheet.txt notion of relaxed
This commit adds a key entry enumerating the various types of relaxed
operations. While in the area, it also renames the relaxed rows.
[ paulmck: Apply Boqun Feng feedback. ]
Acked-by: Boqun Feng <boqun.feng@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
tools/memory-model/Documentation/cheatsheet.txt | 33 +++++++++-------
1 file changed, 19 insertions(+), 14 deletions(-)
diff --git a/tools/memory-model/Documentation/cheatsheet.txt b/tools/memory-model/Documentation/cheatsheet.txt
index 33ba98d..99d0087 100644
--- a/tools/memory-model/Documentation/cheatsheet.txt
+++ b/tools/memory-model/Documentation/cheatsheet.txt
@@ -3,9 +3,9 @@
C Self R W RMW Self R W DR DW RMW SV
-- ---- - - --- ---- - - -- -- --- --
-Store, e.g., WRITE_ONCE() Y Y
-Load, e.g., READ_ONCE() Y Y Y Y
-Unsuccessful RMW operation Y Y Y Y
+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
@@ -17,14 +17,19 @@ 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: 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
+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