From 8559183ccaec97454b2515ac426f113967256cf9 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 14 May 2018 16:33:50 -0700 Subject: [PATCH] tools/memory-model: Remove duplicated code from lock.cat This patch simplifies the implementation of spin_is_locked in the LKMM. It capitalizes on the fact that a failed spin_trylock() and a spin_is_locked() which returns True have exactly the same semantics (those of READ_ONCE) and ordering properties (none). Therefore the two kinds of events can be combined and handled by the same code, instead of treated separately as they are currently. Tested-by: Andrea Parri Signed-off-by: Alan Stern Signed-off-by: Paul E. McKenney Cc: Akira Yokosawa Cc: Andrew Morton Cc: Boqun Feng Cc: David Howells Cc: Jade Alglave Cc: Linus Torvalds Cc: Luc Maranget Cc: Nicholas Piggin Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Cc: linux-arch@vger.kernel.org Cc: parri.andrea@gmail.com Link: http://lkml.kernel.org/r/1526340837-12222-12-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar --- tools/memory-model/lock.cat | 28 ++++++---------------------- 1 file changed, 6 insertions(+), 22 deletions(-) diff --git a/tools/memory-model/lock.cat b/tools/memory-model/lock.cat index 3b1439e..1f6d67e 100644 --- a/tools/memory-model/lock.cat +++ b/tools/memory-model/lock.cat @@ -41,11 +41,15 @@ flag ~empty [FW] ; loc ; [ALL-LOCKS] as lock-final *) let RL = try RL with emptyset (* defined herd7 >= 7.49 *) let RU = try RU with emptyset (* defined herd7 >= 7.49 *) + +(* Treat RL as a kind of LF: a read with no ordering properties *) +let LF = LF | RL + (* * Put lock operations in their appropriate classes, but leave UL out of W * until after the co relation has been generated. *) -let R = R | LKR | LF | RL | RU +let R = R | LKR | LF | RU let W = W | LKW let Release = Release | UL @@ -80,28 +84,8 @@ let all-possible-rfe-lf = (* Generate all rf relations for LF events *) with rfe-lf from cross(all-possible-rfe-lf) - let rf-lf = rfe-lf | rfi-lf -(* rf for RL events, ie islocked returning true, similar to LF above *) - -(* islocked returning true inside a critical section - * must read from the opening lock - *) -let rfi-rl = ([LKW] ; po-loc ; [RL]) \ ([LKW] ; po-loc ; [UL] ; po-loc) - -(* islocked returning true outside critical sections can match any - * external lock. - *) -let all-possible-rfe-rl = - let possible-rfe-lf r = - let pair-to-relation p = p ++ 0 - in map pair-to-relation ((LKW * {r}) & loc & ext) - in map possible-rfe-lf (RL \ range(rfi-rl)) - -with rfe-rl from cross(all-possible-rfe-rl) -let rf-rl = rfe-rl | rfi-rl - (* Read from unlock, ie islocked returning false, slightly different *) (* islocked returning false can read from the last po-previous unlock *) @@ -118,7 +102,7 @@ with rfe-ru from cross(all-possible-rfe-ru) let rf-ru = rfe-ru | rfi-ru (* Final rf relation *) -let rf = rf | rf-lf | rf-rl | rf-ru +let rf = rf | rf-lf | rf-ru (* Generate all co relations, including LKW events but not UL *) let co0 = co0 | ([IW] ; loc ; [LKW]) | -- 2.7.4