Message-ID: <502CFD35.5000801@linux.intel.com>
Date: Thu, 16 Aug 2012 07:01:25 -0700
From: Arjan van de Ven <arjan@linux.intel.com>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:14.0) Gecko/20120713 Thunderbird/14.0
MIME-Version: 1.0
To: preeti <preeti@linux.vnet.ibm.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>, Alex Shi <alex.shi@intel.com>,
        Suresh Siddha <suresh.b.siddha@intel.com>, vincent.guittot@linaro.org,
        svaidy@linux.vnet.ibm.com, Ingo Molnar <mingo@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>, Paul Turner <pjt@google.com>
Subject: Re: [discussion]sched: a rough proposal to enable power saving in
 scheduler
References: <5028F12C.7080405@intel.com> <1345028738.31459.82.camel@twins> <502C98E8.20800@linux.vnet.ibm.com>
In-Reply-To: <502C98E8.20800@linux.vnet.ibm.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 738
Lines: 21

> *Power policy*:
> 
> So how is power policy different? As Peter says,'pack more than spread
> more'.

this is ... a dubiously general statement.

for good power, at least on Intel cpus, you want to spread. Parallelism is efficient.

the only thing you do not want to do, is wake cpus up for
tasks that only run extremely briefly (think "100 usec" or less).

so maybe the balance interval is slightly different, or more, you don't balance tasks that
historically ran only for brief periods


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/