linux/tools/memory-model/Documentation/cheatsheet.txt
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   1                                  Prior Operation     Subsequent Operation
   2                                  ---------------  ---------------------------
   3                               C  Self  R  W  RMW  Self  R  W  DR  DW  RMW  SV
   4                              --  ----  -  -  ---  ----  -  -  --  --  ---  --
   5
   6Relaxed store                        Y                                       Y
   7Relaxed load                         Y                          Y   Y        Y
   8Relaxed RMW operation                Y                          Y   Y        Y
   9rcu_dereference()                    Y                          Y   Y        Y
  10Successful *_acquire()               R                   Y  Y   Y   Y    Y   Y
  11Successful *_release()         C        Y  Y    Y     W                      Y
  12smp_rmb()                               Y       R        Y      Y        R
  13smp_wmb()                                  Y    W           Y       Y    W
  14smp_mb() & synchronize_rcu()  CP        Y  Y    Y        Y  Y   Y   Y    Y
  15Successful full non-void RMW  CP     Y  Y  Y    Y     Y  Y  Y   Y   Y    Y   Y
  16smp_mb__before_atomic()       CP        Y  Y    Y        a  a   a   a    Y
  17smp_mb__after_atomic()        CP        a  a    Y        Y  Y   Y   Y    Y
  18
  19
  20Key:    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
  36