tools/memory-model: Remove out-of-date comments and code from lock.cat

lock.cat contains old comments and code referring to the possibility
of LKR events that are not part of an RMW pair.  This is a holdover
from when I though we might end up using LKR events to implement
spin_is_locked().  Reword the comments to remove this assumption and
replace domain(lk-rmw) in the code with LKR.

Tested-by: Andrea Parri <andrea.parri@amarulasolutions.com>
[ paulmck: Pulled as lock-nest into previous line as discussed. ]
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Akira Yokosawa <akiyks@gmail.com>
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/1526340837-12222-15-git-send-email-paulmck@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Alan Stern 2018-05-14 16:33:53 -07:00 committed by Ingo Molnar
parent 30b795df11
commit cee0321a40
1 changed files with 6 additions and 9 deletions

View File

@ -47,18 +47,15 @@ flag ~empty [M \ IW] ; loc ; [ALL-LOCKS] as mixed-lock-accesses
let lk-rmw = ([LKR] ; po-loc ; [LKW]) \ (po ; po)
let rmw = rmw | lk-rmw
(* The litmus test is invalid if an LKR/LKW event is not part of an RMW pair *)
flag ~empty LKW \ range(lk-rmw) as unpaired-LKW
flag ~empty LKR \ domain(lk-rmw) as unpaired-LKR
(*
* A paired LKR must always see an unlocked value; spin_lock() calls nested
* An LKR must always see an unlocked value; spin_lock() calls nested
* inside a critical section (for the same lock) always deadlock.
*)
empty ([LKW] ; po-loc ; [domain(lk-rmw)]) \ (po-loc ; [UL] ; po-loc)
as lock-nest
(* The litmus test is invalid if an LKW event is not part of an RMW pair *)
flag ~empty LKW \ range(lk-rmw) as unpaired-LKW
(* This will be allowed if we implement spin_is_locked() *)
flag ~empty LKR \ domain(lk-rmw) as unpaired-LKR
empty ([LKW] ; po-loc ; [LKR]) \ (po-loc ; [UL] ; po-loc) as lock-nest
(* The final value of a spinlock should not be tested *)
flag ~empty [FW] ; loc ; [ALL-LOCKS] as lock-final