From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <nfont@austin.ibm.com>
Received: from e3.ny.us.ibm.com (e3.ny.us.ibm.com [32.97.182.143])
	(using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
	(Client CN "e3.ny.us.ibm.com", Issuer "Equifax" (verified OK))
	by ozlabs.org (Postfix) with ESMTPS id 3808BB70A8
	for <linuxppc-dev@ozlabs.org>; Tue, 10 Aug 2010 03:53:33 +1000 (EST)
Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237])
	by e3.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id o79Hc5bh001655
	for <linuxppc-dev@ozlabs.org>; Mon, 9 Aug 2010 13:38:05 -0400
Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217])
	by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id
	o79Hr4KS125526
	for <linuxppc-dev@ozlabs.org>; Mon, 9 Aug 2010 13:53:04 -0400
Received: from d01av03.pok.ibm.com (loopback [127.0.0.1])
	by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id
	o79Hr2ku030947
	for <linuxppc-dev@ozlabs.org>; Mon, 9 Aug 2010 14:53:04 -0300
Message-ID: <4C60407C.2080608@austin.ibm.com>
Date: Mon, 09 Aug 2010 12:53:00 -0500
From: Nathan Fontenot <nfont@austin.ibm.com>
MIME-Version: 1.0
To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@ozlabs.org
Subject: [PATCH 0/8] v5 De-couple sysfs memory directories from memory sections
Content-Type: text/plain; charset=ISO-8859-1
Cc: Greg KH <greg@kroah.com>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	Dave Hansen <dave@linux.vnet.ibm.com>
List-Id: Linux on PowerPC Developers Mail List <linuxppc-dev.lists.ozlabs.org>
List-Unsubscribe: <https://lists.ozlabs.org/options/linuxppc-dev>,
	<mailto:linuxppc-dev-request@lists.ozlabs.org?subject=unsubscribe>
List-Archive: <http://lists.ozlabs.org/pipermail/linuxppc-dev>
List-Post: <mailto:linuxppc-dev@lists.ozlabs.org>
List-Help: <mailto:linuxppc-dev-request@lists.ozlabs.org?subject=help>
List-Subscribe: <https://lists.ozlabs.org/listinfo/linuxppc-dev>,
	<mailto:linuxppc-dev-request@lists.ozlabs.org?subject=subscribe>

This set of patches de-couples the idea that there is a single
directory in sysfs for each memory section.  The intent of the
patches is to reduce the number of sysfs directories created to
resolve a boot-time performance issue.  On very large systems
boot time are getting very long (as seen on powerpc hardware)
due to the enormous number of sysfs directories being created.
On a system with 1 TB of memory we create ~63,000 directories.
For even larger systems boot times are being measured in hours.

This set of patches allows for each directory created in sysfs
to cover more than one memory section.  The default behavior for
sysfs directory creation is the same, in that each directory
represents a single memory section.  A new file 'end_phys_index'
in each directory contains the physical_id of the last memory
section covered by the directory so that users can easily
determine the memory section range of a directory.

Updates for version 5 of the patchset include the following:

Patch 4/8 Add mutex for add/remove of memory blocks
- Define the mutex using DEFINE_MUTEX macro.

Patch 8/8 Update memory-hotplug documentation
- Add information concerning memory holes in phys_index..end_phys_index.
 
Thanks,

Nathan Fontenot