From: Mathieu Desnoyers <compudj@krystal.dyndns.org>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: ltt-dev@lists.casi.polymtl.ca, bert.wesarg@googlemail.com,
bob@watson.ibm.com, linux-kernel@vger.kernel.org
Subject: Re: [[PATCH URCU formal]] Restructure urcu_updater() to more accurately reflect actual failure scenario.
Date: Fri, 20 Feb 2009 12:15:26 -0500 [thread overview]
Message-ID: <20090220171526.GG1179@Krystal> (raw)
In-Reply-To: <20090220015747.GA19488@linux.vnet.ibm.com>
* Paul E. McKenney (paulmck@linux.vnet.ibm.com) wrote:
> Restructure urcu_updater() to more accurately reflect actual failure
> scenario.
>
> This allows an easier transformation to force failure -- simple #ifdef
> out the second counter flip out of urcu_updater()'s model of
> "current synchronize_rcu()".
>
Merged, thanks !
Mathieu
> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
> ---
> formal-model/urcu.spin | 41 +++++++++++++++++++++++++++++++----------
> 1 files changed, 31 insertions(+), 10 deletions(-)
>
> diff --git a/formal-model/urcu.spin b/formal-model/urcu.spin
> index eea18e8..3e18457 100644
> --- a/formal-model/urcu.spin
> +++ b/formal-model/urcu.spin
> @@ -187,10 +187,38 @@ proctype urcu_reader()
>
> proctype urcu_updater()
> {
> + /* prior synchronize_rcu(), second counter flip. */
> + need_mb = 1;
> + do
> + :: need_mb == 1 -> skip;
> + :: need_mb == 0 -> break;
> + od;
> + urcu_gp_ctr = urcu_gp_ctr + RCU_GP_CTR_BIT;
> + need_mb = 1;
> + do
> + :: need_mb == 1 -> skip;
> + :: need_mb == 0 -> break;
> + od;
> + do
> + :: 1 ->
> + if
> + :: (urcu_active_readers & RCU_GP_CTR_NEST_MASK) != 0 &&
> + (urcu_active_readers & ~RCU_GP_CTR_NEST_MASK) !=
> + (urcu_gp_ctr & ~RCU_GP_CTR_NEST_MASK) ->
> + skip;
> + :: else -> break;
> + fi;
> + od;
> + need_mb = 1;
> + do
> + :: need_mb == 1 -> skip;
> + :: need_mb == 0 -> break;
> + od;
> +
> /* Removal statement, e.g., list_del_rcu(). */
> removed = 1;
>
> - /* synchronize_rcu(), first counter flip. */
> + /* current synchronize_rcu(), first counter flip. */
> need_mb = 1;
> do
> :: need_mb == 1 -> skip;
> @@ -204,15 +232,13 @@ proctype urcu_updater()
> od;
> do
> :: 1 ->
> - printf("urcu_gp_ctr=%x urcu_active_readers=%x\n", urcu_gp_ctr, urcu_active_readers);
> - printf("urcu_gp_ctr&0x7f=%x urcu_active_readers&0x7f=%x\n", urcu_gp_ctr & ~RCU_GP_CTR_NEST_MASK, urcu_active_readers & ~RCU_GP_CTR_NEST_MASK);
> if
> :: (urcu_active_readers & RCU_GP_CTR_NEST_MASK) != 0 &&
> (urcu_active_readers & ~RCU_GP_CTR_NEST_MASK) !=
> (urcu_gp_ctr & ~RCU_GP_CTR_NEST_MASK) ->
> skip;
> :: else -> break;
> - fi
> + fi;
> od;
> need_mb = 1;
> do
> @@ -220,10 +246,7 @@ proctype urcu_updater()
> :: need_mb == 0 -> break;
> od;
>
> - /* Erroneous removal statement, e.g., list_del_rcu(). */
> - /* removed = 1; */
> -
> - /* synchronize_rcu(), second counter flip. */
> + /* current synchronize_rcu(), second counter flip. */
> need_mb = 1;
> do
> :: need_mb == 1 -> skip;
> @@ -237,8 +260,6 @@ proctype urcu_updater()
> od;
> do
> :: 1 ->
> - printf("urcu_gp_ctr=%x urcu_active_readers=%x\n", urcu_gp_ctr, urcu_active_readers);
> - printf("urcu_gp_ctr&0x7f=%x urcu_active_readers&0x7f=%x\n", urcu_gp_ctr & ~RCU_GP_CTR_NEST_MASK, urcu_active_readers & ~RCU_GP_CTR_NEST_MASK);
> if
> :: (urcu_active_readers & RCU_GP_CTR_NEST_MASK) != 0 &&
> (urcu_active_readers & ~RCU_GP_CTR_NEST_MASK) !=
> --
> 1.5.2.5
>
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
prev parent reply other threads:[~2009-02-20 17:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-20 1:57 [[PATCH URCU formal]] Restructure urcu_updater() to more accurately reflect actual failure scenario Paul E. McKenney
2009-02-20 17:15 ` Mathieu Desnoyers [this message]
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