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Commit 7246a966 authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'lkmm-for-mingo' of... 

Merge branch 'lkmm-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

 into locking/urgent

Pull the "Linux kernel memory model" tooling implementation from Paul E. McKenney:

 'This pull request contains a single commit that adds a memory model to
  the tools directory.  This memory model can (roughly speaking) be thought
  of as an automated version of memory-barriers.txt.  It is written in the
  "cat" language, which is executable by the externally provided "herd7"
  simulator, which exhaustively explores the state space of small litmus
  tests.'

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
parents 72906f38 1c27b644

tools/memory-model/Documentation/cheatsheet.txt

0 → 100644
+30 −0
Original line number Diff line number Diff line 
                                  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

smp_read_barrier_depends()              Y                       Y   Y

*_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





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

	SV	Same-variable access