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| author | Alan Stern <stern@rowland.harvard.edu> | 2018-03-07 09:27:40 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-03-10 10:22:23 +0100 |
| commit | bd5c0ba2cd78a4c116726ead84f8f37dc92d043e (patch) | |
| tree | 96b7c86c9fd330c270d7d4296c7b88da1fc1df59 /tools/memory-model/Documentation/cheatsheet.txt | |
| parent | ff1fe5e079730f138c98b268ce2e8482a1d954b4 (diff) | |
| download | linux-stable-bd5c0ba2cd78a4c116726ead84f8f37dc92d043e.tar.gz linux-stable-bd5c0ba2cd78a4c116726ead84f8f37dc92d043e.tar.bz2 linux-stable-bd5c0ba2cd78a4c116726ead84f8f37dc92d043e.zip | |
tools/memory-model: Finish the removal of rb-dep, smp_read_barrier_depends(), and lockless_dereference()
Commit:
bf28ae562744 ("tools/memory-model: Remove rb-dep, smp_read_barrier_depends, and lockless_dereference")
was merged too early, while it was still in RFC form. This patch adds in
the missing pieces.
Akira pointed out some typos in the original patch, and he noted that
cheatsheet.txt should indicate that READ_ONCE() now implies an address
dependency. Andrea suggested documenting the relationship betwwen
unsuccessful RMW operations and address dependencies.
Andrea pointed out that the macro for rcu_dereference() in linux.def
should now use the "once" annotation instead of "deref". He also
suggested that the comments should mention commit:
5a8897cc7631 ("locking/atomics/alpha: Add smp_read_barrier_depends() to _release()/_relaxed() atomics")
... as an important precursor, and he contributed commit:
cb13b424e986 ("locking/xchg/alpha: Add unconditional memory barrier to cmpxchg()")
which is another prerequisite.
Suggested-by: Akira Yokosawa <akiyks@gmail.com>
Suggested-by: Andrea Parri <parri.andrea@gmail.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
[ Fixed read_read_lock() typo reported by Akira. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Andrea Parri <parri.andrea@gmail.com>
Acked-by: Akira Yokosawa <akiyks@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boqun.feng@gmail.com
Cc: dhowells@redhat.com
Cc: j.alglave@ucl.ac.uk
Cc: linux-arch@vger.kernel.org
Cc: luc.maranget@inria.fr
Cc: npiggin@gmail.com
Cc: will.deacon@arm.com
Fixes: bf28ae562744 ("tools/memory-model: Remove rb-dep, smp_read_barrier_depends, and lockless_dereference")
Link: http://lkml.kernel.org/r/1520443660-16858-4-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/memory-model/Documentation/cheatsheet.txt')
| -rw-r--r-- | tools/memory-model/Documentation/cheatsheet.txt | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/tools/memory-model/Documentation/cheatsheet.txt b/tools/memory-model/Documentation/cheatsheet.txt index 04e458acd6d4..956b1ae4aafb 100644 --- a/tools/memory-model/Documentation/cheatsheet.txt +++ b/tools/memory-model/Documentation/cheatsheet.txt @@ -1,11 +1,11 @@ Prior Operation Subsequent Operation --------------- --------------------------- C Self R W RWM Self R W DR DW RMW SV - __ ---- - - --- ---- - - -- -- --- -- + -- ---- - - --- ---- - - -- -- --- -- Store, e.g., WRITE_ONCE() Y Y -Load, e.g., READ_ONCE() Y Y Y -Unsuccessful RMW operation Y Y Y +Load, e.g., READ_ONCE() Y Y Y Y +Unsuccessful 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 |