bfd403bb36
The current cheat sheet does not claim that smp_mb__after_atomic() orders later RMW atomic operations, which it must, at least against earlier RMW atomic operations and whatever precedes them. This commit therefore adds the needed "Y". Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: akiyks@gmail.com 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: parri.andrea@gmail.com Link: http://lkml.kernel.org/r/1526340837-12222-6-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
31 lines
1.7 KiB
Plaintext
31 lines
1.7 KiB
Plaintext
Prior Operation Subsequent Operation
|
|
--------------- ---------------------------
|
|
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
|
|
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: 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
|