From: Frederic Weisbecker <fweisbec@gmail.com>
To: paulmck@linux.vnet.ibm.com
Cc: Li Zhong <zhong@linux.vnet.ibm.com>,
linux-next list <linux-next@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
sasha.levin@oracle.com, gleb@redhat.com, avi@redhat.com
Subject: Re: [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to async page fault
Date: Tue, 27 Nov 2012 17:31:14 +0100 [thread overview]
Message-ID: <CAFTL4hw5fgZccTMhV81OxVVfitUtqWXQi9djTCPJz7-4ff35Pg@mail.gmail.com> (raw)
In-Reply-To: <20121127161639.GF2474@linux.vnet.ibm.com>
2012/11/27 Paul E. McKenney <paulmck@linux.vnet.ibm.com>:
> It is OK to call rcu_irq_exit() without a matching rcu_irq_enter() -only-
> if you have also called rcu_idle_exit() since the last rcu_idle_enter().
> There will be a similar rule for rcu_user_exit().
>
> More generally, it is OK to call rcu_irq_exit() without a matching
> rcu_irq_enter() only if RCU believes that the CPU you are running on is
> non-idle.
Perfect!
> On 32-bit systems, you are only allowed a few tens of million
> such unmatched rcu_irq_enter() calls in a given RCU-non-idle region.
>
> All courtesy of RCU's need to tolerate architectures that enter
> interrupt handlers without ever leaving them and vice versa. ;-)
RCU idle mode in a hostile environment ;-)
next prev parent reply other threads:[~2012-11-27 16:32 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-27 5:15 [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to async page fault Li Zhong
2012-11-27 5:58 ` [PATCH rcu] use new nesting value for rcu_dyntick trace in rcu_eqs_enter_common Li Zhong
2012-11-27 15:18 ` Paul E. McKenney
2012-11-27 13:07 ` [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to async page fault Gleb Natapov
2012-11-27 14:01 ` Sasha Levin
2012-11-27 15:25 ` Paul E. McKenney
2012-11-27 15:34 ` Frederic Weisbecker
2012-11-27 14:38 ` Frederic Weisbecker
2012-11-27 15:44 ` Gleb Natapov
2012-11-27 15:56 ` Frederic Weisbecker
2012-11-27 16:19 ` Paul E. McKenney
2012-11-27 16:48 ` Frederic Weisbecker
2012-11-27 16:59 ` Paul E. McKenney
2012-11-27 16:39 ` Gleb Natapov
2012-11-27 16:51 ` Frederic Weisbecker
2012-11-27 17:00 ` Gleb Natapov
2012-11-27 17:30 ` Frederic Weisbecker
2012-11-27 17:47 ` Gleb Natapov
2012-11-27 18:12 ` Frederic Weisbecker
2012-11-27 19:27 ` Gleb Natapov
2012-11-27 22:53 ` Frederic Weisbecker
2012-11-27 22:54 ` Frederic Weisbecker
2012-11-27 15:39 ` Frederic Weisbecker
2012-11-27 16:16 ` Paul E. McKenney
2012-11-27 16:31 ` Frederic Weisbecker [this message]
2012-11-27 16:29 ` Frederic Weisbecker
2012-11-28 8:18 ` [RFC PATCH v2] Add rcu user eqs exception hooks for " Li Zhong
2012-11-28 12:55 ` Frederic Weisbecker
2012-11-28 13:53 ` Gleb Natapov
2012-11-28 14:25 ` Frederic Weisbecker
2012-11-29 11:07 ` Gleb Natapov
2012-11-29 14:47 ` Frederic Weisbecker
2012-11-30 9:18 ` [RFC PATCH v3] " Li Zhong
2012-11-30 10:26 ` Gleb Natapov
2012-12-03 2:08 ` Li Zhong
2012-12-03 8:30 ` Gleb Natapov
2012-12-03 9:57 ` Gleb Natapov
2012-12-04 2:35 ` [ PATCH] " Li Zhong
2012-12-18 13:25 ` Gleb Natapov
2012-12-04 2:36 ` [RFC PATCH v3] " Li Zhong
2012-12-04 5:11 ` Gleb Natapov
2012-12-04 5:40 ` Li Zhong
2012-12-04 13:02 ` Gleb Natapov
2012-12-04 14:28 ` Paul E. McKenney
2012-11-29 1:49 ` [RFC PATCH v2] " Li Zhong
2012-11-29 14:40 ` Frederic Weisbecker
2012-11-29 17:25 ` Gleb Natapov
2012-11-30 8:36 ` Li Zhong
2012-11-30 10:08 ` Gleb Natapov
2012-11-27 16:43 ` [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to " Frederic Weisbecker
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