From: Arjan van de Ven <arjan@linux.intel.com>
To: paulmck@linux.vnet.ibm.com
Cc: Jacob Pan <jacob.jun.pan@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 13:56:45 -0800 [thread overview]
Message-ID: <50A2C21D.6070108@linux.intel.com> (raw)
In-Reply-To: <20121113211602.GA30150@linux.vnet.ibm.com>
On 11/13/2012 1:16 PM, Paul E. McKenney wrote:
> On Mon, Nov 12, 2012 at 02:03:51PM -0800, Jacob Pan wrote:
>> Intel PowerClamp driver performs synchronized idle injection across
>> all online CPUs. The goal is to maintain a given package level C-state
>> ratio.
>>
>> Compared to other throttling methods already exist in the kernel,
>> such as ACPI PAD (taking CPUs offline) and clock modulation, this is often
>> more efficient in terms of performance per watt.
>>
>> Please refer to Documentation/thermal/intel_powerclamp.txt for more details.
>
> If I read this correctly, this forces a group of CPUs into idle for
> about 600 milliseconds at a time. This would indeed delay grace periods,
6ms not 600
prev parent reply other threads:[~2012-11-13 21:56 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
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 [this message]
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