From: Andi Kleen <andi@firstfloor.org>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andi Kleen <andi@firstfloor.org>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>,
Linux Kernel <linux-kernel@vger.kernel.org>,
Suresh B Siddha <suresh.b.siddha@intel.com>,
Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>,
Arjan van de Ven <arjan@infradead.org>,
Ingo Molnar <mingo@elte.hu>, Dipankar Sarma <dipankar@in.ibm.com>,
Balbir Singh <balbir@linux.vnet.ibm.com>,
Vatsa <vatsa@linux.vnet.ibm.com>,
Gautham R Shenoy <ego@in.ibm.com>,
Gregory Haskins <gregory.haskins@gmail.com>,
Mike Galbraith <efault@gmx.de>,
Thomas Gleixner <tglx@linutronix.de>,
Arun Bharadwaj <arun@linux.vnet.ibm.com>
Subject: Re: [RFC PATCH v2 0/2] Saving power by cpu evacuation sched_max_capacity_pct=n
Date: Wed, 13 May 2009 16:46:59 +0200 [thread overview]
Message-ID: <20090513144659.GV19296@one.firstfloor.org> (raw)
In-Reply-To: <1242225402.26820.23.camel@twins>
On Wed, May 13, 2009 at 04:36:42PM +0200, Peter Zijlstra wrote:
> On Wed, 2009-05-13 at 16:35 +0200, Andi Kleen wrote:
> > On Wed, May 13, 2009 at 06:41:00PM +0530, Vaidyanathan Srinivasan wrote:
> > > * Using sched_mc=3,4,5 to evacuate 1,2,4 cores is completely
> > > non-intuitive and broken interface. Ingo wanted to see if we can
> > > model a global percentile tunable that would map to core throttling.
> >
> > I have one request. CPU throttling is already a very well established
> > term in the x86 world, refering to thermal throttling when the CPU
> > overheats. This is implemented by ACPI and the CPU. It's always
> > a very bad thing that should be avoided at all costs.
>
> Its about avoiding that.
Hmm? Can you explain please? CPU throttling should only happen when your
cooling system is broken in some way.
It's not a power saving feature, just a "don't make CPU melt" feature.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
next prev parent reply other threads:[~2009-05-13 14:41 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-13 13:11 [RFC PATCH v2 0/2] Saving power by cpu evacuation sched_max_capacity_pct=n Vaidyanathan Srinivasan
2009-05-13 13:11 ` [RFC PATCH v2 1/2] sched: add sched_max_capacity_pct Vaidyanathan Srinivasan
2009-05-13 13:11 ` [RFC PATCH v2 2/2] sched: loadbalancer hacks for forced packing of tasks Vaidyanathan Srinivasan
2009-05-13 13:14 ` [RFC PATCH v2 0/2] Saving power by cpu evacuation sched_max_capacity_pct=n Peter Zijlstra
2009-05-13 13:42 ` [RFC PATCH v2 0/2] Saving power by cpu evacuationsched_max_capacity_pct=n Vaidyanathan Srinivasan
2009-05-13 13:45 ` Balbir Singh
2009-05-13 13:47 ` Peter Zijlstra
2009-05-13 14:42 ` [RFC PATCH v2 0/2] Saving power by cpuevacuationsched_max_capacity_pct=n Balbir Singh
2009-05-13 14:35 ` [RFC PATCH v2 0/2] Saving power by cpu evacuation sched_max_capacity_pct=n Andi Kleen
2009-05-13 14:36 ` Peter Zijlstra
2009-05-13 14:46 ` Andi Kleen [this message]
2009-05-13 14:50 ` Peter Zijlstra
2009-05-13 15:01 ` Andi Kleen
2009-05-13 15:02 ` Peter Zijlstra
2009-05-13 15:10 ` Andi Kleen
2009-05-14 14:58 ` Vaidyanathan Srinivasan
2009-05-14 15:06 ` Andi Kleen
2009-05-14 15:43 ` Vaidyanathan Srinivasan
2009-05-14 15:13 ` Vaidyanathan Srinivasan
2009-05-19 20:40 ` Pavel Machek
2009-05-22 9:14 ` Vaidyanathan Srinivasan
2009-05-28 20:36 ` Pavel Machek
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