mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 04:18:39 +08:00
1a00b4554d
ASPLOS 2018 was held in March: make sure this is reflected in header comments and references. Signed-off-by: Andrea Parri <andrea.parri@amarulasolutions.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Akira Yokosawa <akiyks@gmail.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Jade Alglave <j.alglave@ucl.ac.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luc Maranget <luc.maranget@inria.fr> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arch@vger.kernel.org Cc: parri.andrea@gmail.com Link: http://lkml.kernel.org/r/1526340837-12222-18-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
129 lines
3.7 KiB
Plaintext
129 lines
3.7 KiB
Plaintext
// SPDX-License-Identifier: GPL-2.0+
|
|
(*
|
|
* Copyright (C) 2015 Jade Alglave <j.alglave@ucl.ac.uk>,
|
|
* Copyright (C) 2016 Luc Maranget <luc.maranget@inria.fr> for Inria
|
|
* Copyright (C) 2017 Alan Stern <stern@rowland.harvard.edu>,
|
|
* Andrea Parri <parri.andrea@gmail.com>
|
|
*
|
|
* An earlier version of this file appeared in the companion webpage for
|
|
* "Frightening small children and disconcerting grown-ups: Concurrency
|
|
* in the Linux kernel" by Alglave, Maranget, McKenney, Parri, and Stern,
|
|
* which appeared in ASPLOS 2018.
|
|
*)
|
|
|
|
"Linux-kernel memory consistency model"
|
|
|
|
(*
|
|
* File "lock.cat" handles locks and is experimental.
|
|
* It can be replaced by include "cos.cat" for tests that do not use locks.
|
|
*)
|
|
|
|
include "lock.cat"
|
|
|
|
(*******************)
|
|
(* Basic relations *)
|
|
(*******************)
|
|
|
|
(* Fences *)
|
|
let rmb = [R \ Noreturn] ; fencerel(Rmb) ; [R \ Noreturn]
|
|
let wmb = [W] ; fencerel(Wmb) ; [W]
|
|
let mb = ([M] ; fencerel(Mb) ; [M]) |
|
|
([M] ; fencerel(Before-atomic) ; [RMW] ; po? ; [M]) |
|
|
([M] ; po? ; [RMW] ; fencerel(After-atomic) ; [M]) |
|
|
([M] ; po? ; [LKW] ; fencerel(After-spinlock) ; [M])
|
|
let gp = po ; [Sync-rcu] ; po?
|
|
|
|
let strong-fence = mb | gp
|
|
|
|
(* Release Acquire *)
|
|
let acq-po = [Acquire] ; po ; [M]
|
|
let po-rel = [M] ; po ; [Release]
|
|
let rfi-rel-acq = [Release] ; rfi ; [Acquire]
|
|
|
|
(**********************************)
|
|
(* Fundamental coherence ordering *)
|
|
(**********************************)
|
|
|
|
(* Sequential Consistency Per Variable *)
|
|
let com = rf | co | fr
|
|
acyclic po-loc | com as coherence
|
|
|
|
(* Atomic Read-Modify-Write *)
|
|
empty rmw & (fre ; coe) as atomic
|
|
|
|
(**********************************)
|
|
(* Instruction execution ordering *)
|
|
(**********************************)
|
|
|
|
(* Preserved Program Order *)
|
|
let dep = addr | data
|
|
let rwdep = (dep | ctrl) ; [W]
|
|
let overwrite = co | fr
|
|
let to-w = rwdep | (overwrite & int)
|
|
let to-r = addr | (dep ; rfi) | rfi-rel-acq
|
|
let fence = strong-fence | wmb | po-rel | rmb | acq-po
|
|
let ppo = to-r | to-w | fence
|
|
|
|
(* Propagation: Ordering from release operations and strong fences. *)
|
|
let A-cumul(r) = rfe? ; r
|
|
let cumul-fence = A-cumul(strong-fence | po-rel) | wmb
|
|
let prop = (overwrite & ext)? ; cumul-fence* ; rfe?
|
|
|
|
(*
|
|
* Happens Before: Ordering from the passage of time.
|
|
* No fences needed here for prop because relation confined to one process.
|
|
*)
|
|
let hb = ppo | rfe | ((prop \ id) & int)
|
|
acyclic hb as happens-before
|
|
|
|
(****************************************)
|
|
(* Write and fence propagation ordering *)
|
|
(****************************************)
|
|
|
|
(* Propagation: Each non-rf link needs a strong fence. *)
|
|
let pb = prop ; strong-fence ; hb*
|
|
acyclic pb as propagation
|
|
|
|
(*******)
|
|
(* RCU *)
|
|
(*******)
|
|
|
|
(*
|
|
* Effect of read-side critical section proceeds from the rcu_read_lock()
|
|
* onward on the one hand and from the rcu_read_unlock() backwards on the
|
|
* other hand.
|
|
*)
|
|
let rscs = po ; crit^-1 ; po?
|
|
|
|
(*
|
|
* The synchronize_rcu() strong fence is special in that it can order not
|
|
* one but two non-rf relations, but only in conjunction with an RCU
|
|
* read-side critical section.
|
|
*)
|
|
let rcu-link = hb* ; pb* ; prop
|
|
|
|
(*
|
|
* Any sequence containing at least as many grace periods as RCU read-side
|
|
* 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) |
|
|
(rcu-fence ; rcu-link ; rcu-fence)
|
|
|
|
(* rb orders instructions just as pb does *)
|
|
let rb = prop ; rcu-fence ; hb* ; pb*
|
|
|
|
irreflexive rb as rcu
|
|
|
|
(*
|
|
* The happens-before, propagation, and rcu constraints are all
|
|
* expressions of temporal ordering. They could be replaced by
|
|
* a single constraint on an "executes-before" relation, xb:
|
|
*
|
|
* let xb = hb | pb | rb
|
|
* acyclic xb as executes-before
|
|
*)
|