Commit 0172d9e3 authored by Alan Stern's avatar Alan Stern Committed by Paul E. McKenney
Browse files

tools/memory-model: Rename some RCU relations 



In preparation for adding support for SRCU, rename "crit" to
"rcu-rscs", rename "rscs" to "rcu-rscsi", and remove the restriction
to only the outermost level of nesting.

The name change is needed for disambiguating RCU read-side critical
sections from SRCU read-side critical sections.  Adding the "i" at the
end of "rcu-rscsi" emphasizes that the relation is inverted; it links
rcu_read_unlock() events to their corresponding preceding
rcu_read_lock() events.

The restriction to outermost nesting levels was never essential; it
was included mostly to show that it could be done.  Rather than add
equivalent unnecessary code for SRCU lock nesting, it seemed better to
remove the existing code.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
Tested-by: default avatarAndrea Parri <andrea.parri@amarulasolutions.com>
parent 9e98c678

tools/memory-model/linux-kernel.bell

+3 −6
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ enum Barriers = 'wmb (*smp_wmb*) || 
instructions F[Barriers]



(* Compute matching pairs of nested Rcu-lock and Rcu-unlock *)

let matched = let rec

let rcu-rscs = let rec

	    unmatched-locks = Rcu-lock \ domain(matched)

	and unmatched-unlocks = Rcu-unlock \ range(matched)

	and unmatched = unmatched-locks | unmatched-unlocks
@@ -46,8 +46,5 @@ let matched = let rec 
	in matched



(* Validate nesting *)

flag ~empty Rcu-lock \ domain(matched) as unbalanced-rcu-locking

flag ~empty Rcu-unlock \ range(matched) as unbalanced-rcu-locking



(* Outermost level of nesting only *)

let crit = matched \ (po^-1 ; matched ; po^-1)
 
flag ~empty Rcu-lock \ domain(rcu-rscs) as unbalanced-rcu-locking

flag ~empty Rcu-unlock \ range(rcu-rscs) as unbalanced-rcu-locking

tools/memory-model/linux-kernel.cat

+5 −5
Original line number Diff line number Diff line
@@ -95,7 +95,7 @@ acyclic pb as propagation 
 * onward on the one hand and from the rcu_read_unlock() backwards on the

 * other hand.

 *)

let rscs = po ; crit^-1 ; po?

let rcu-rscsi = po ; rcu-rscs^-1 ; po?



(*

 * The synchronize_rcu() strong fence is special in that it can order not
@@ -109,10 +109,10 @@ let rcu-link = hb* ; pb* ; prop 
 * critical sections (joined by rcu-link) acts as a generalized strong fence.

 *)

let rec rcu-fence = gp |

	(gp ; rcu-link ; rscs) |

	(rscs ; rcu-link ; gp) |

	(gp ; rcu-link ; rcu-fence ; rcu-link ; rscs) |

	(rscs ; rcu-link ; rcu-fence ; rcu-link ; gp) |

	(gp ; rcu-link ; rcu-rscsi) |

	(rcu-rscsi ; rcu-link ; gp) |

	(gp ; rcu-link ; rcu-fence ; rcu-link ; rcu-rscsi) |

	(rcu-rscsi ; rcu-link ; rcu-fence ; rcu-link ; gp) |

	(rcu-fence ; rcu-link ; rcu-fence)



(* rb orders instructions just as pb does *)

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