From patchwork Fri Jan 21 21:15:42 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tim Gardner X-Patchwork-Id: 79935 X-Patchwork-Delegate: tim.gardner@canonical.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id 72562B70E3 for ; Sat, 22 Jan 2011 08:16:03 +1100 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1PgOKi-0004Lg-2p; Fri, 21 Jan 2011 21:15:48 +0000 Received: from mail.tpi.com ([70.99.223.143]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1PgOKg-0004LY-AB for kernel-team@lists.ubuntu.com; Fri, 21 Jan 2011 21:15:46 +0000 Received: from sepang.rtg.net (unknown [10.0.2.5]) by mail.tpi.com (Postfix) with ESMTP id 8BE18277642 for ; Fri, 21 Jan 2011 13:15:44 -0800 (PST) Received: by sepang.rtg.net (Postfix, from userid 1000) id 3B86FF89F8; Fri, 21 Jan 2011 14:15:42 -0700 (MST) To: kernel-team@lists.ubuntu.com Subject: Maverick SRU, CONFIG_NR_CPUS=256, LP706058 Message-Id: <20110121211542.3B86FF89F8@sepang.rtg.net> Date: Fri, 21 Jan 2011 14:15:42 -0700 (MST) From: timg@tpi.com (Tim Gardner) X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com The following changes since commit fd6181c23bea04ff5a7e85cfaf8fdd7233ca2422: Manoj Iyer (1): Quirk to fix suspend/resume on Lenovo Edge 11,13,14,15 are available in the git repository at: git://kernel.ubuntu.com/rtg/ubuntu-maverick.git nr_cpus_256_lp706058 Tim Gardner (1): UBUNTU: [Config] Set CONFIG_NR_CPUS=256 for amd64 server debian.master/config/amd64/config.common.amd64 | 1 - debian.master/config/amd64/config.flavour.generic | 1 + debian.master/config/amd64/config.flavour.server | 1 + debian.master/config/amd64/config.flavour.virtual | 1 + 4 files changed, 3 insertions(+), 1 deletions(-) From 4c706219417d6f8491a83f1095b5fee916a342cd Mon Sep 17 00:00:00 2001 From: Tim Gardner Date: Fri, 21 Jan 2011 14:12:56 -0700 Subject: [PATCH] UBUNTU: [Config] Set CONFIG_NR_CPUS=256 for amd64 server BugLink: http://bugs.launchpad.net/bugs/706058 The CPU hotplug subsytem allocates memory using the per-cpu mechanism. Enough memory is pre-defined by CONFIG_NR_CPUS to accommodate the maximum number of CPUs that can be online. This value is discovered at boot time and is used to trim the actual memory allocated to the real number of CPUs. In effect, CONFIG_NR_CPUS has little impact on memory consumption except for these 9 vairables: kernel/cpu.c:static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly kernel/cpu.c:static DECLARE_BITMAP(cpu_possible_bits, CONFIG_NR_CPUS) __read_mostly; kernel/cpu.c:static DECLARE_BITMAP(cpu_online_bits, CONFIG_NR_CPUS) __read_mostly; kernel/cpu.c:static DECLARE_BITMAP(cpu_present_bits, CONFIG_NR_CPUS) __read_mostly; kernel/cpu.c:static DECLARE_BITMAP(cpu_active_bits, CONFIG_NR_CPUS) __read_mostly; kernel/sched.c: DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); kernel/sched.c: DECLARE_BITMAP(span, CONFIG_NR_CPUS); kernel/sched.c: static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); mm/slub.c:static DECLARE_BITMAP(kmem_cach_cpu_free_init_once, CONFIG_NR_CPUS); The increase in memory size of these variables is negligible since they are bit map structures. For example, increasing from 64 to 256 only adds 24 bytes per variable. Signed-off-by: Tim Gardner Acked-by: Brad Figg Acked-by: Stefan Bader --- debian.master/config/amd64/config.common.amd64 | 1 - debian.master/config/amd64/config.flavour.generic | 1 + debian.master/config/amd64/config.flavour.server | 1 + debian.master/config/amd64/config.flavour.virtual | 1 + 4 files changed, 3 insertions(+), 1 deletions(-)