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From: Frederic Weisbecker <fweisbec@gmail.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Alessio Igor Bogani <abogani@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Avi Kivity <avi@redhat.com>, Chris Metcalf <cmetcalf@tilera.com>,
	Christoph Lameter <cl@linux.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Geoff Levand <geoff@infradead.org>,
	Gilad Ben Yossef <gilad@benyossef.com>,
	Hakan Akkan <hakanakkan@gmail.com>, Kevin Hilman <khilman@ti.com>,
	Max Krasnyansky <maxk@qualcomm.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Stephen Hemminger <shemminger@vyatta.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Sven-Thorsten Dietrich <thebigcorporation@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 0/2] rcu: Extended quiescent state for adaptive nohz
Date: Sun, 10 Jun 2012 00:58:56 +0200	[thread overview]
Message-ID: <20120609225852.GC31957@somewhere.redhat.com> (raw)
In-Reply-To: <20120607224508.GX19601@linux.vnet.ibm.com>

On Thu, Jun 07, 2012 at 03:45:08PM -0700, Paul E. McKenney wrote:
> > I can see you've implemented a version for TinyRCU. Nohz cpusets only work on
> > SMP right now because there must be at least one CPU running with the tick
> > to maintain the timekeeping. I'm pretty confident that one day we'll remove
> > the jiffies and we'll be able to do the whole timekeeping by using the TSC
> > or so. There is quite a way before we reach that though.
> 
> In the meantime, would it make sense to slow the tick rate by a factor
> of 10 or so on that one CPU when nothing else is going on?  Or does
> timekeeping absolutely require running the tick at full speed?

I'm not sure of the possible consequences of that.

  reply	other threads:[~2012-06-09 22:59 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-04 12:08 [PATCH 0/2] rcu: Extended quiescent state for adaptive nohz fweisbec
2012-06-04 12:08 ` [PATCH 1/2] rcu: New rcu_user_enter() and rcu_user_exit() APIs fweisbec
2012-06-04 12:08 ` [PATCH 2/2] rcu: New rcu_user_enter_irq() and rcu_user_exit_irq() APIs fweisbec
2012-06-04 18:13 ` [PATCH 0/2] rcu: Extended quiescent state for adaptive nohz Paul E. McKenney
2012-06-04 19:06   ` Frederic Weisbecker
2012-06-04 21:07     ` Paul E. McKenney
2012-06-05 10:31       ` Frederic Weisbecker
2012-06-05 23:46         ` Paul E. McKenney
2012-06-07 14:21           ` Frederic Weisbecker
2012-06-07 22:45             ` Paul E. McKenney
2012-06-09 22:58               ` Frederic Weisbecker [this message]
2012-06-10 17:54                 ` Paul E. McKenney
2012-06-09 22:55           ` [PATCH] rcu: Allow calls to rcu_exit_user_irq from nesting irqs Frederic Weisbecker
2012-06-10 18:06             ` Paul E. McKenney
2012-06-10 20:29               ` Frederic Weisbecker
2012-06-10 21:47               ` [PATCH v2] " Frederic Weisbecker
2012-06-11 21:55                 ` Paul E. McKenney
2012-06-11 22:06                   ` Frederic Weisbecker

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