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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/tools/memory-model/Documentation/cheatsheet.txt
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                                  Prior Operation     Subsequent Operation

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                                  ---------------  ---------------------------

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                               C  Self  R  W  RMW  Self  R  W  DR  DW  RMW  SV

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                              --  ----  -  -  ---  ----  -  -  --  --  ---  --

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Relaxed store                        Y                                       Y

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Relaxed load                         Y                          Y   Y        Y

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Relaxed RMW operation                Y                          Y   Y        Y

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rcu_dereference()                    Y                          Y   Y        Y

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Successful *_acquire()               R                   Y  Y   Y   Y    Y   Y

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Successful *_release()         C        Y  Y    Y     W                      Y

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smp_rmb()                               Y       R        Y      Y        R

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smp_wmb()                                  Y    W           Y       Y    W

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smp_mb() & synchronize_rcu()  CP        Y  Y    Y        Y  Y   Y   Y    Y

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Successful full non-void RMW  CP     Y  Y  Y    Y     Y  Y  Y   Y   Y    Y   Y

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smp_mb__before_atomic()       CP        Y  Y    Y        a  a   a   a    Y

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smp_mb__after_atomic()        CP        a  a    Y        Y  Y   Y   Y    Y

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Key:	Relaxed:  A relaxed operation is either READ_ONCE(), WRITE_ONCE(),

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		  a *_relaxed() RMW operation, an unsuccessful RMW

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		  operation, a non-value-returning RMW operation such

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		  as atomic_inc(), or one of the atomic*_read() and

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		  atomic*_set() family of operations.

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	C:	  Ordering is cumulative

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	P:	  Ordering propagates

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	R:	  Read, for example, READ_ONCE(), or read portion of RMW

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	W:	  Write, for example, WRITE_ONCE(), or write portion of RMW

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	Y:	  Provides ordering

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	a:	  Provides ordering given intervening RMW atomic operation

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	DR:	  Dependent read (address dependency)

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	DW:	  Dependent write (address, data, or control dependency)

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	RMW:	  Atomic read-modify-write operation

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	SELF:	  Orders self, as opposed to accesses before and/or after

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	SV:	  Orders later accesses to the same variable

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