tools/memory-model/Documentation/cheatsheet.txt

   1                                   Prior Operation     Subsequent Operation
   2                                   ---------------  ---------------------------
   3                                C  Self  R  W  RMW  Self  R  W  DR  DW  RMW  SV
   4                               --  ----  -  -  ---  ----  -  -  --  --  ---  --
   5
   6 Relaxed store                        Y                                       Y
   7 Relaxed load                         Y                          Y   Y        Y
   8 Relaxed RMW operation                Y                          Y   Y        Y
   9 rcu_dereference()                    Y                          Y   Y        Y
  10 Successful *_acquire()               R                   Y  Y   Y   Y    Y   Y
  11 Successful *_release()         C        Y  Y    Y     W                      Y
  12 smp_rmb()                               Y       R        Y      Y        R
  13 smp_wmb()                                  Y    W           Y       Y    W
  14 smp_mb() & synchronize_rcu()  CP        Y  Y    Y        Y  Y   Y   Y    Y
  15 Successful full non-void RMW  CP     Y  Y  Y    Y     Y  Y  Y   Y   Y    Y   Y
  16 smp_mb__before_atomic()       CP        Y  Y    Y        a  a   a   a    Y
  17 smp_mb__after_atomic()        CP        a  a    Y        Y  Y   Y   Y    Y
  18
  19
  20 Key:    Relaxed:  A relaxed operation is either READ_ONCE(), WRITE_ONCE(),
  21                   a *_relaxed() RMW operation, an unsuccessful RMW
  22                   operation, a non-value-returning RMW operation such
  23                   as atomic_inc(), or one of the atomic*_read() and
  24                   atomic*_set() family of operations.
  25         C:        Ordering is cumulative
  26         P:        Ordering propagates
  27         R:        Read, for example, READ_ONCE(), or read portion of RMW
  28         W:        Write, for example, WRITE_ONCE(), or write portion of RMW
  29         Y:        Provides ordering
  30         a:        Provides ordering given intervening RMW atomic operation
  31         DR:       Dependent read (address dependency)
  32         DW:       Dependent write (address, data, or control dependency)
  33         RMW:      Atomic read-modify-write operation
  34         SELF:     Orders self, as opposed to accesses before and/or after
  35         SV:       Orders later accesses to the same variable