Commit-ID: cee0321a404fe6b43d1f4364639c8ffe2f2b37d1 Gitweb: https://git.kernel.org/tip/cee0321a404fe6b43d1f4364639c8ffe2f2b37d1 Author: Alan Stern <st...@rowland.harvard.edu> AuthorDate: Mon, 14 May 2018 16:33:53 -0700 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Tue, 15 May 2018 08:11:18 +0200
tools/memory-model: Remove out-of-date comments and code from lock.cat lock.cat contains old comments and code referring to the possibility of LKR events that are not part of an RMW pair.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.pa...@amarulasolutions.com> [ paulmck: Pulled as lock-nest into previous line as discussed. ] Signed-off-by: Alan Stern <st...@rowland.harvard.edu> Signed-off-by: Paul E. McKenney <paul...@linux.vnet.ibm.com> Cc: Akira Yokosawa <aki...@gmail.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Boqun Feng <boqun.f...@gmail.com> Cc: David Howells <dhowe...@redhat.com> Cc: Jade Alglave <j.algl...@ucl.ac.uk> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Luc Maranget <luc.maran...@inria.fr> Cc: Nicholas Piggin <npig...@gmail.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Will Deacon <will.dea...@arm.com> Cc: linux-a...@vger.kernel.org Cc: parri.and...@gmail.com Link: http://lkml.kernel.org/r/1526340837-12222-15-git-send-email-paul...@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- tools/memory-model/lock.cat | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-) diff --git a/tools/memory-model/lock.cat b/tools/memory-model/lock.cat index 7217cd4941a4..cd002a33ca8a 100644 --- a/tools/memory-model/lock.cat +++ b/tools/memory-model/lock.cat @@ -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
