From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932520AbWHQSQi (ORCPT ); Thu, 17 Aug 2006 14:16:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932567AbWHQSQi (ORCPT ); Thu, 17 Aug 2006 14:16:38 -0400 Received: from mga06.intel.com ([134.134.136.21]:45673 "EHLO orsmga101.jf.intel.com") by vger.kernel.org with ESMTP id S932520AbWHQSQh (ORCPT ); Thu, 17 Aug 2006 14:16:37 -0400 X-ExtLoop1: 1 X-IronPort-AV: i="4.08,139,1154934000"; d="scan'208"; a="110298817:sNHT2094870603" Date: Thu, 17 Aug 2006 11:03:17 -0700 From: "Siddha, Suresh B" To: Paul Jackson Cc: "Siddha, Suresh B" , akpm@osdl.org, linux-kernel@vger.kernel.org, nickpiggin@yahoo.com.au, mingo@redhat.com, apw@shadowen.org Subject: Re: [patch] sched: group CPU power setup cleanup Message-ID: <20060817110317.A14787@unix-os.sc.intel.com> References: <20060815175525.A2333@unix-os.sc.intel.com> <20060815212455.c9fe1e34.pj@sgi.com> <20060815214718.00814767.akpm@osdl.org> <20060816110357.B7305@unix-os.sc.intel.com> <20060817102030.f8c41330.pj@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20060817102030.f8c41330.pj@sgi.com>; from pj@sgi.com on Thu, Aug 17, 2006 at 10:20:30AM -0700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 17, 2006 at 10:20:30AM -0700, Paul Jackson wrote: > > It refers to group's processing power. Perhaps "horsepower" is better term. > > Well ... I don't think "horsepower" is a step in the right direction. > > Andrew's point was over the word "power", not "cpu". The term > "cpu_power" suggested to him we were concerned with the power supply > watts consumed by a group of CPUs. Indeed, both those concerned with > laptop battery lifetimes, and the air conditioning tonnage needed > for big honkin NUMA iron might have reason to be concerned with the > power consumed by CPUs. > > Changing the word "cpu" to "horse", but keeping the word "power", > does nothing to address Andrew's point. Rather it just adds more > confusion. We are obviously dealing with CPUs here, not horses. Let me resist the temptation and not go into the definition of horsepower here. You can refer any dictionary. > My understanding is that the "cpu_power" of the cpus in a sched group > is rougly proportional to the BogoMIPS of the CPUs in that group. This variable represents how many tasks(multiplied by scaling factor SCHED_LOAD_SCALE)the group can handle before it starts distributing the load to other idle or less lightly loaded groups. For example, group with two HT threads will have it as < 2 * SCHED_LOAD_SCALE. group with N physical cpus in a NUMA node will have it as N * SCHED_LOAD_SCALE. When power savings policy is enabled, some of the domains group values will increase making each group pickup more load and save some watt power. "group_capacity" or "load_capacity" might be good term considering all this.. thanks, suresh