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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>,
	"Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>,
	Arjan van de Ven <arjan@infradead.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	"Rafael J. Wysocki" <rjw@sisk.pl>,
	Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	Paul Gortmaker <paul.gortmaker@windriver.com>,
	Milton Miller <miltonm@bga.com>, "mingo@elte.hu" <mingo@elte.hu>,
	Tejun Heo <tj@kernel.org>,
	KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Linux PM mailing list <linux-pm@vger.kernel.org>
Subject: Re: CPU Hotplug rework
Date: Fri, 23 Mar 2012 17:23:47 -0700	[thread overview]
Message-ID: <20120324002347.GD2450@linux.vnet.ibm.com> (raw)
In-Reply-To: <877gya99uj.fsf@rustcorp.com.au>

On Sat, Mar 24, 2012 at 09:57:32AM +1030, Rusty Russell wrote:
> On Thu, 22 Mar 2012 15:49:20 -0700, "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote:
> > On Thu, Mar 22, 2012 at 02:55:04PM +1030, Rusty Russell wrote:
> > > On Wed, 21 Mar 2012 10:01:59 +0100, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> > > > Thing is, if its really too much for some people, they can orchestrate
> > > > it such that its not. Just move everybody in a cpuset, clear the to be
> > > > offlined cpu from the cpuset's mask -- this will migrate everybody away.
> > > > Then hotplug will find an empty runqueue and its fast, no?
> > > 
> > > I like this solution better.
> > 
> > As long as we have some way to handle kthreads that are algorithmically
> > tied to a given CPU.  There are coding conventions to handle this, for
> > example, do everything with preemption disabled and just after each
> > preempt_disable() verify that you are in fact running on the correct
> > CPU, but it is easy to imagine improvements.
> 
> I don't think we should move per-cpu kthreads at all.  Let's stop trying
> to save a few bytes of memory, and just leave them frozen.  They'll run
> again if/when the CPU returns.

OK, that would work for me.  So, how do I go about freezing RCU's
per-CPU kthreads?

							Thanx, Paul


  reply	other threads:[~2012-03-24  0:24 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-19 14:44 CPU Hotplug rework Srivatsa S. Bhat
2012-03-19 14:48 ` Srivatsa S. Bhat
2012-03-20 11:28   ` Peter Zijlstra
2012-04-05 17:39   ` Paul E. McKenney
2012-04-05 17:55     ` Paul E. McKenney
2012-04-05 23:06       ` Paul E. McKenney
2012-04-06 20:15         ` Srivatsa S. Bhat
2012-04-09 16:46           ` Paul E. McKenney
2012-04-10  7:56             ` Nikunj A Dadhania
2012-04-06 19:52     ` Srivatsa S. Bhat
2012-04-09 17:13       ` Paul E. McKenney
2012-04-10 13:41         ` Srivatsa S. Bhat
2012-04-10 15:46           ` Paul E. McKenney
2012-04-10 17:26             ` Srivatsa S. Bhat
2012-04-11  0:09       ` Steven Rostedt
2012-04-11  0:28         ` Paul E. McKenney
2012-04-11  0:37           ` Steven Rostedt
2012-04-11  1:00             ` Paul E. McKenney
2012-04-11  6:02               ` Srivatsa S. Bhat
2012-04-11 12:28                 ` Paul E. McKenney
2012-03-19 23:42 ` Rusty Russell
2012-03-20 10:42   ` Peter Zijlstra
2012-03-20 23:00     ` Rusty Russell
2012-03-21  9:01       ` Peter Zijlstra
2012-03-22  4:25         ` Rusty Russell
2012-03-22 22:49           ` Paul E. McKenney
2012-03-23 23:27             ` Rusty Russell
2012-03-24  0:23               ` Paul E. McKenney [this message]
2012-03-26  0:41                 ` Rusty Russell
2012-03-26  8:02                   ` Peter Zijlstra
2012-03-26 13:09                     ` Steven Rostedt
2012-03-26 13:38                       ` Peter Zijlstra
2012-03-26 15:22                         ` Steven Rostedt
2012-03-26 16:13                           ` Peter Zijlstra
2012-03-26 17:05                             ` Steven Rostedt
2012-03-26 17:59                               ` Peter Zijlstra
2012-03-27  1:32                               ` Rusty Russell
2012-03-27  3:05                                 ` Steven Rostedt

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