From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753314AbXLFKuH (ORCPT ); Thu, 6 Dec 2007 05:50:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751978AbXLFKt5 (ORCPT ); Thu, 6 Dec 2007 05:49:57 -0500 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:44617 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751391AbXLFKt4 (ORCPT ); Thu, 6 Dec 2007 05:49:56 -0500 Date: Thu, 06 Dec 2007 19:48:11 +0900 From: Yasunori Goto To: Geert Uytterhoeven Subject: Re: PS3: trouble with SPARSEMEM_VMEMMAP and kexec Cc: Geoff Levand , Andrew Morton , miltonm@bga.com, clameter@sgi.com, apw@shadowen.org, linux-kernel@vger.kernel.org In-Reply-To: References: X-Mailer-Plugin: BkASPil for Becky!2 Ver.2.068 Message-Id: <20071206191717.6955.Y-GOTO@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.27 [ja] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Thu, 6 Dec 2007, Geert Uytterhoeven wrote: > > On Thu, 6 Dec 2007, Yasunori Goto wrote: > > > > I'll try Milton's suggestion to pre-allocate the memory early. It seems > > > > that should work as long as nothing else before the hot-plug mem is added > > > > needs a large chunk. > > > > > > Hello. Geoff-san. Sorry for late response. > > > > > > Could you tell me the value of the following page_size calculation > > > in vmemmap_populate()? I think this page_size may be too big value. > > > > > > ------ > > > int __meminit vmemmap_populate(struct page *start_page, > > > unsigned long nr_pages, int node) > > > : > > > : > > > unsigned long page_size = 1 << mmu_psize_defs[mmu_linear_psize].shift; > > > : > > > ------- > > > > 24 MiB > > Bummer, messing up bits and MiB. > > 16 MiB of course. 16 MiB is not page size. It is "section size". IIRC, powerpc's page size must be 4K (or 64K). If page size is 4k, vmemmap_alloc_block will call the order 12 page. Is it really correct value for vmemmap population? > PS3 initially starts with 128 MiB. > Later hotplug is used to add the remaining memory (96 or 112 MIB, IIRC). Ok. Then, add_memory() must be called 6 or 7 times for each sections. Thanks. -- Yasunori Goto