From: Steven Rostedt <rostedt@goodmis.org>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Joel Fernandes <joelaf@google.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: rcu-bh design
Date: Fri, 4 May 2018 13:37:26 -0400 [thread overview]
Message-ID: <20180504133726.3f04d7bf@gandalf.local.home> (raw)
In-Reply-To: <20180504173205.GQ26088@linux.vnet.ibm.com>
On Fri, 4 May 2018 10:32:06 -0700
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote:
> > > But preemptible RCU *does not* use context-switch as a quiescent state.
> >
> > It doesn't?
>
> It does, but only sort of.
Ah, my confusion. I was thinking of rcu_read_lock_sched() as
"preemptible RCU", not the "we can preempt in rcu_read_lock() context".
-- Steve
>
> A context switch really is always an RCU-preempt quiescent state from
> the perspective of the CPU. However, from the perspective of the task,
> context switch is a quiescent state only if the task is not in an
> RCU-preempt read-side critical section at the time.
prev parent reply other threads:[~2018-05-04 17:37 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-04 16:20 rcu-bh design Joel Fernandes
2018-05-04 16:30 ` Steven Rostedt
2018-05-04 17:15 ` Joel Fernandes
2018-05-04 17:43 ` Paul E. McKenney
2018-05-04 18:34 ` Joel Fernandes
2018-05-04 18:49 ` Paul E. McKenney
2018-05-04 19:57 ` Joel Fernandes
2018-05-04 20:11 ` Paul E. McKenney
2018-05-04 20:33 ` Joel Fernandes
2018-05-04 22:49 ` Paul E. McKenney
2018-05-04 23:20 ` Joel Fernandes
2018-05-04 23:43 ` Paul E. McKenney
2018-05-05 0:39 ` Joel Fernandes
2018-05-04 17:32 ` Paul E. McKenney
2018-05-04 17:37 ` Steven Rostedt [this message]
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