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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>,
	Linux PM <linux-pm@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Rafael Wysocki <rafael.j.wysocki@intel.com>,
	Len Brown <len.brown@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>,
	Zhang Rui <rui.zhang@intel.com>, Rob Landley <rob@landley.net>
Subject: Re: [PATCH 3/3] PM: Introduce Intel PowerClamp Driver
Date: Tue, 13 Nov 2012 17:34:59 -0800	[thread overview]
Message-ID: <20121114013459.GS2489@linux.vnet.ibm.com> (raw)
In-Reply-To: <20121113171450.3657290c@chromoly>

On Tue, Nov 13, 2012 at 05:14:50PM -0800, Jacob Pan wrote:
> On Tue, 13 Nov 2012 16:08:54 -0800
> Arjan van de Ven <arjan@linux.intel.com> wrote:
> 
> > > I think I know, but I feel the need to ask anyway.  Why not tell
> > > RCU about the clamping?  
> > 
> > I don't mind telling RCU, but what cannot happen is a bunch of CPU
> > time suddenly getting used (since that is the opposite of what is
> > needed at the specific point in time of going idle)

Another round of RCU_FAST_NO_HZ rework, you are asking for?  ;-)

> Another reason is my observation that there are some assumptions/checks
> to make sure only idle thread can tell rcu it is idle. Is it ok to
> extend that to other kthreads?

If you are only having the system take 6-millisecond "vacations", probably
best to try it as it is and fix specific problems if/when they arise.

							Thanx, Paul


  reply	other threads:[~2012-11-14  1:36 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-12 22:03 [PATCH 0/3] pm: Intel powerclamp driver Jacob Pan
2012-11-12 22:03 ` [PATCH 1/3] tick: export nohz tick idle symbols for module use Jacob Pan
2012-11-12 22:03 ` [PATCH 2/3] x86/nmi: export local_touch_nmi() symbol for modules Jacob Pan
2012-11-12 22:03 ` [PATCH 3/3] PM: Introduce Intel PowerClamp Driver Jacob Pan
2012-11-13  6:33   ` Joe Perches
2012-11-13  6:55     ` Jacob Pan
2012-11-13 21:16   ` Paul E. McKenney
2012-11-13 21:39     ` Jacob Pan
2012-11-13 22:23       ` Paul E. McKenney
2012-11-13 22:45         ` Arjan van de Ven
2012-11-13 23:02           ` Rafael J. Wysocki
2012-11-14  0:03             ` Paul E. McKenney
2012-11-14  0:03           ` Paul E. McKenney
2012-11-14  0:08             ` Arjan van de Ven
2012-11-14  1:14               ` Jacob Pan
2012-11-14  1:34                 ` Paul E. McKenney [this message]
2012-11-14  2:59                   ` Arjan van de Ven
2012-11-15  3:22                     ` Paul E. McKenney
2012-11-14  1:24             ` Jacob Pan
2012-11-13 21:56     ` Arjan van de Ven

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