From: Peter Zijlstra <peterz@infradead.org>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>,
linux-kernel@vger.kernel.org, mingo@kernel.org,
laijs@cn.fujitsu.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
tglx@linutronix.de, rostedt@goodmis.org, dhowells@redhat.com,
edumazet@google.com, dvhart@linux.intel.com, fweisbec@gmail.com,
oleg@redhat.com, bobby.prani@gmail.com
Subject: Re: [PATCH RFC tip/core/rcu 0/5] Expedited grace periods encouraging normal ones
Date: Wed, 1 Jul 2015 12:12:21 +0200 [thread overview]
Message-ID: <20150701101221.GS19282@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20150701033701.GV3717@linux.vnet.ibm.com>
On Tue, Jun 30, 2015 at 08:37:01PM -0700, Paul E. McKenney wrote:
> > Wait, what? Why is anything using traditional (non-S) RCU while *any*
> > lock is held?
>
> In their defense, it is a sleeplock that is never taken except when
> rearranging networking configuration. Sometimes they need a grace period
> under the lock. So synchronize_net() checks to see if RTNL is held, and
> does a synchronize_rcu_expedited() if so and a synchronize_rcu() if not.
Sounds vile.
next prev parent reply other threads:[~2015-07-01 10:12 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-06-30 21:48 [PATCH RFC tip/core/rcu 0/5] Expedited grace periods encouraging normal ones Paul E. McKenney
2015-06-30 21:48 ` [PATCH RFC tip/core/rcu 1/5] rcu: Prepare for expedited GP driving normal GP Paul E. McKenney
2015-06-30 21:48 ` [PATCH RFC tip/core/rcu 2/5] rcu: Short-circuit normal GPs via expedited GPs Paul E. McKenney
2015-07-01 10:03 ` Peter Zijlstra
2015-07-01 13:42 ` Paul E. McKenney
2015-07-01 20:59 ` Paul E. McKenney
2015-07-01 10:05 ` Peter Zijlstra
2015-07-01 13:41 ` Paul E. McKenney
2015-07-01 13:48 ` Peter Zijlstra
2015-07-01 14:03 ` Paul E. McKenney
2015-07-02 12:03 ` Peter Zijlstra
2015-07-02 14:06 ` Paul E. McKenney
2015-07-02 16:48 ` Peter Zijlstra
2015-07-02 19:35 ` Paul E. McKenney
2015-07-06 14:52 ` Peter Zijlstra
2015-06-30 21:48 ` [PATCH RFC tip/core/rcu 3/5] rcutorture: Ensure that normal GPs advance without " Paul E. McKenney
2015-06-30 21:48 ` [PATCH RFC tip/core/rcu 4/5] rcu: Wake grace-period kthread at end of expedited grace period Paul E. McKenney
2015-06-30 21:48 ` [PATCH RFC tip/core/rcu 5/5] rcu: Limit expedited helping to every 10 ms or every 4th GP Paul E. McKenney
2015-06-30 21:56 ` Eric Dumazet
2015-06-30 22:10 ` Paul E. McKenney
2015-07-01 10:07 ` Peter Zijlstra
2015-07-01 13:45 ` Paul E. McKenney
2015-07-01 19:30 ` Paul E. McKenney
2015-06-30 22:00 ` [PATCH RFC tip/core/rcu 0/5] Expedited grace periods encouraging normal ones josh
2015-06-30 22:12 ` Paul E. McKenney
2015-06-30 23:46 ` josh
2015-07-01 0:15 ` Paul E. McKenney
2015-07-01 0:42 ` Josh Triplett
2015-07-01 3:37 ` Paul E. McKenney
2015-07-01 10:12 ` Peter Zijlstra [this message]
2015-07-01 14:01 ` Paul E. McKenney
2015-07-01 14:08 ` Eric Dumazet
2015-07-01 15:58 ` Paul E. McKenney
2015-07-01 15:43 ` Josh Triplett
2015-07-01 15:59 ` Paul E. McKenney
2015-07-01 10:09 ` Peter Zijlstra
2015-07-01 10:55 ` Peter Zijlstra
2015-07-01 14:00 ` Paul E. McKenney
2015-07-01 14:17 ` Peter Zijlstra
2015-07-01 16:17 ` Paul E. McKenney
2015-07-01 17:02 ` Peter Zijlstra
2015-07-01 20:09 ` Paul E. McKenney
2015-07-01 21:20 ` josh
2015-07-01 21:49 ` Paul E. McKenney
2015-07-02 7:47 ` Ingo Molnar
2015-07-02 13:58 ` Paul E. McKenney
2015-07-02 18:35 ` Ingo Molnar
2015-07-02 18:47 ` Mathieu Desnoyers
2015-07-02 19:23 ` Paul E. McKenney
2015-07-02 21:07 ` Mathieu Desnoyers
2015-07-02 19:22 ` Paul E. McKenney
2015-07-02 1:11 ` Mike Galbraith
2015-07-02 1:34 ` josh
2015-07-02 1:59 ` Mike Galbraith
2015-07-02 2:18 ` Paul E. McKenney
2015-07-02 2:50 ` Mike Galbraith
2015-07-02 3:15 ` Paul E. McKenney
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