Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763846AbYJJVe2 (ORCPT ); Fri, 10 Oct 2008 17:34:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762611AbYJJVeH (ORCPT ); Fri, 10 Oct 2008 17:34:07 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:53864 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764245AbYJJVeE (ORCPT ); Fri, 10 Oct 2008 17:34:04 -0400 Date: Fri, 10 Oct 2008 14:33:57 -0700 From: Gary Hade To: Andrew Morton Cc: Gary Hade , linux-mm@kvack.org, linux-kernel@vger.kernel.org, y-goto@jp.fujitsu.com, pbadari@us.ibm.com, mel@csn.ul.ie, lcm@us.ibm.com, mingo@elte.hu, greg@kroah.com, dave@linux.vnet.ibm.com, nish.aravamudan@gmail.com Subject: Re: [PATCH 1/2] [REPOST] mm: show node to memory section relationship with symlinks in sysfs Message-ID: <20081010213357.GD7369@us.ibm.com> References: <20081009192115.GB8793@us.ibm.com> <20081010124239.f92b5568.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081010124239.f92b5568.akpm@linux-foundation.org> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1655 Lines: 40 On Fri, Oct 10, 2008 at 12:42:39PM -0700, Andrew Morton wrote: > On Thu, 9 Oct 2008 12:21:15 -0700 > Gary Hade wrote: > > > Show node to memory section relationship with symlinks in sysfs > > > > Add /sys/devices/system/node/nodeX/memoryY symlinks for all > > the memory sections located on nodeX. For example: > > /sys/devices/system/node/node1/memory135 -> ../../memory/memory135 > > indicates that memory section 135 resides on node1. > > I'm not seeing here a description of why the kernel needs this feature. > Why is it useful? How will it be used? What value does it have to > our users? Sorry, I should have included that. In our case, it is another small step towards eventual total node removal. We will need to know which memory sections to offline for whatever node is targeted for removal. However, I suspect that exposing the node to section information to user-level could be useful for other purposes. For example, I have been thinking that using memory hotremove functionality to modify the amount of available memory on specific nodes without having to physically add/remove DIMMs might be useful to those that test application or benchmark performance on a multi-node system in various memory configurations. Gary -- Gary Hade System x Enablement IBM Linux Technology Center 503-578-4503 IBM T/L: 775-4503 garyhade@us.ibm.com http://www.ibm.com/linux/ltc -- 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/