From patchwork Mon Aug 9 18:43:46 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nathan Fontenot X-Patchwork-Id: 61306 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from bilbo.ozlabs.org (localhost [127.0.0.1]) by ozlabs.org (Postfix) with ESMTP id 8C950B7CBB for ; Tue, 10 Aug 2010 04:44:33 +1000 (EST) Received: by ozlabs.org (Postfix) id 8E01DB7104; Tue, 10 Aug 2010 04:44:23 +1000 (EST) Delivered-To: linuxppc-dev@ozlabs.org Received: from e38.co.us.ibm.com (e38.co.us.ibm.com [32.97.110.159]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e38.co.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 15DE2B70DF for ; Tue, 10 Aug 2010 04:44:22 +1000 (EST) Received: from d03relay01.boulder.ibm.com (d03relay01.boulder.ibm.com [9.17.195.226]) by e38.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id o79Iawik022321 for ; Mon, 9 Aug 2010 12:36:59 -0600 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay01.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o79Ii5f9152854 for ; Mon, 9 Aug 2010 12:44:05 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id o79Ii4ww023354 for ; Mon, 9 Aug 2010 12:44:05 -0600 Received: from [9.76.215.50] (sig-9-76-215-50.mts.ibm.com [9.76.215.50]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id o79Ii3Qh021592; Mon, 9 Aug 2010 12:44:03 -0600 Message-ID: <4C604C62.7060509@austin.ibm.com> Date: Mon, 09 Aug 2010 13:43:46 -0500 From: Nathan Fontenot User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.11) Gecko/20100713 Thunderbird/3.0.6 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@ozlabs.org Subject: [PATCH 8/8] v5 Update memory-hotplug documentation References: <4C60407C.2080608@austin.ibm.com> In-Reply-To: <4C60407C.2080608@austin.ibm.com> Cc: Greg KH , KAMEZAWA Hiroyuki , Dave Hansen X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Update the memory hotplug documentation to reflect the new behaviors of memory blocks reflected in sysfs. Signed-off-by: Nathan Fontent --- Documentation/memory-hotplug.txt | 46 +++++++++++++++++++++++++-------------- 1 file changed, 30 insertions(+), 16 deletions(-) Index: linux-2.6/Documentation/memory-hotplug.txt =================================================================== --- linux-2.6.orig/Documentation/memory-hotplug.txt 2010-08-09 07:36:48.000000000 -0500 +++ linux-2.6/Documentation/memory-hotplug.txt 2010-08-09 07:59:54.000000000 -0500 @@ -126,36 +126,50 @@ config options. -------------------------------- 4 sysfs files for memory hotplug -------------------------------- -All sections have their device information under /sys/devices/system/memory as +All sections have their device information in sysfs. Each section is part of +a memory block under /sys/devices/system/memory as /sys/devices/system/memory/memoryXXX -(XXX is section id.) +(XXX is the section id.) -Now, XXX is defined as start_address_of_section / section_size. +Now, XXX is defined as (start_address_of_section / section_size) of the first +section contained in the memory block. The files 'phys_index' and +'end_phys_index' under each directory report the beginning and end section id's +for the memory block covered by the sysfs directory. It is expected that all +memory sections in this range are present and no memory holes exist in the +range. Currently there is no way to determine if there is a memory hole, but +the existence of one should not affect the hotplug capabilities of the memory +block. For example, assume 1GiB section size. A device for a memory starting at 0x100000000 is /sys/device/system/memory/memory4 (0x100000000 / 1Gib = 4) This device covers address range [0x100000000 ... 0x140000000) -Under each section, you can see 4 files. +Under each section, you can see 5 files. -/sys/devices/system/memory/memoryXXX/phys_index +/sys/devices/system/memory/memoryXXX/start_phys_index +/sys/devices/system/memory/memoryXXX/end_phys_index /sys/devices/system/memory/memoryXXX/phys_device /sys/devices/system/memory/memoryXXX/state /sys/devices/system/memory/memoryXXX/removable -'phys_index' : read-only and contains section id, same as XXX. -'state' : read-write - at read: contains online/offline state of memory. - at write: user can specify "online", "offline" command -'phys_device': read-only: designed to show the name of physical memory device. - This is not well implemented now. -'removable' : read-only: contains an integer value indicating - whether the memory section is removable or not - removable. A value of 1 indicates that the memory - section is removable and a value of 0 indicates that - it is not removable. +'phys_index' : read-only and contains section id of the first section + in the memory block, same as XXX. +'end_phys_index' : read-only and contains section id of the last section + in the memory block. +'state' : read-write + at read: contains online/offline state of memory. + at write: user can specify "online", "offline" command + which will be performed on al sections in the block. +'phys_device' : read-only: designed to show the name of physical memory + device. This is not well implemented now. +'removable' : read-only: contains an integer value indicating + whether the memory block is removable or not + removable. A value of 1 indicates that the memory + block is removable and a value of 0 indicates that + it is not removable. A memory block is removable only if + every section in the block is removable. NOTE: These directories/files appear after physical memory hotplug phase.