From 0ce0c78eff7d22c8a261de6c4305a5abb638c200 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 4 Aug 2020 11:35:56 -0700 Subject: [PATCH] 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 Signed-off-by: Paul E. McKenney --- .../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 33ba98d72b16..99d00870b160 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