Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757989Ab1FPTkd (ORCPT ); Thu, 16 Jun 2011 15:40:33 -0400 Received: from wolverine02.qualcomm.com ([199.106.114.251]:7417 "EHLO wolverine02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757775Ab1FPTkb (ORCPT ); Thu, 16 Jun 2011 15:40:31 -0400 X-IronPort-AV: E=McAfee;i="5400,1158,6379"; a="98001773" Message-ID: <4DFA5C2E.40507@codeaurora.org> Date: Thu, 16 Jun 2011 12:40:30 -0700 From: Stephen Boyd User-Agent: Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9.2.17) Gecko/20110414 Thunderbird/3.1.10 MIME-Version: 1.0 To: Vincent Guittot CC: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linaro-dev@lists.linaro.org Subject: Re: [RFC] Add Arm cpu topology definition References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1868 Lines: 52 On 06/16/2011 01:49 AM, Vincent Guittot wrote: > +config SCHED_MC > + bool "Multi-core scheduler support" > + depends on SMP && ARM_CPU_TOPOLOGY > + default n > + help > + Multi-core scheduler support improves the CPU scheduler's decision > + making when dealing with multi-core CPU chips at a cost of slightly > + increased overhead in some places. If unsure say N here. > + > +config SCHED_SMT > + bool "SMT scheduler support" > + depends on SMP && ARM_CPU_TOPOLOGY > + default n > + help > + Improves the CPU scheduler's decision making when dealing with > + MultiThreading at a cost of slightly increased overhead in some > + places. If unsure say N here. > + The default is already n so you can drop those two lines. > + * This is a multiprocessor system > + * multiprocessor format & multiprocessor mode field are set > + */ > + > + if (mpidr & (0x1 << 24)) { > + /* core performance interdependency */ > + cpuid_topo->thread_id = (mpidr & 0x3); > + cpuid_topo->core_id = ((mpidr >> 8) & 0xF); > + cpuid_topo->socket_id = ((mpidr >> 16) & 0xFF); > + } else { > + /* normal core interdependency */ > + cpuid_topo->thread_id = -1; > + cpuid_topo->core_id = (mpidr & 0x3); > + cpuid_topo->socket_id = ((mpidr >> 8) & 0xF); > + } > + The ARM ARM says these fields are IMPLEMENTATION DEFINED meaning that different vendors may attribute different meaning to these fields if they wish. Does that mean this should be a platform_*() function? -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum. -- 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/