From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933150Ab2GDJUU (ORCPT ); Wed, 4 Jul 2012 05:20:20 -0400 Received: from cantor2.suse.de ([195.135.220.15]:51698 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755736Ab2GDJUO (ORCPT ); Wed, 4 Jul 2012 05:20:14 -0400 Date: Wed, 4 Jul 2012 10:20:06 +0100 From: Mel Gorman To: Jiang Liu Cc: Andrew Morton , Tony Luck , Yinghai Lu , Xishi Qiu , KAMEZAWA Hiroyuki , KOSAKI Motohiro , David Rientjes , Minchan Kim , Keping Chen , linux-mm@kvack.org, stable@vger.kernel.org, linux-kernel@vger.kernel.org, Jiang Liu Subject: Re: [PATCH] mm: setup pageblock_order before it's used by sparse Message-ID: <20120704092006.GH14154@suse.de> References: <1341047274-5616-1-git-send-email-jiang.liu@huawei.com> <20120703140705.af23d4d3.akpm@linux-foundation.org> <4FF39F0E.4070300@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <4FF39F0E.4070300@huawei.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 04, 2012 at 09:40:30AM +0800, Jiang Liu wrote: > > It's a bit ugly calling set_pageblock_order() from both sparse_init() > > and from free_area_init_core(). Can we find a single place from which > > to call it? It looks like here: > > > > --- a/init/main.c~a > > +++ a/init/main.c > > @@ -514,6 +514,7 @@ asmlinkage void __init start_kernel(void > > __stop___param - __start___param, > > -1, -1, &unknown_bootoption); > > > > + set_pageblock_order(); > > jump_label_init(); > > > > /* > > > > would do the trick? > > > > (free_area_init_core is __paging_init and set_pageblock_order() is > > __init. I'm too lazy to work out if that's wrong) > > Hi Andrew, > Thanks for you comments. Yes, this's an issue. > And we are trying to find a way to setup pageorder_block as > early as possible. Yinghai has suggested a good way for IA64, > but we still need help from PPC experts because PPC has the > same issue and I'm not familiar with PPC architecture. > We will submit another patch once we find an acceptable > solution here. I think it's overkill to try and do this on a per-architecture basis unless you are aware of a case where the per-architecture code cares about the value of pageblock_order. I find it implausible that the architecture needs to know the value very early in boot as pageblock_order is part of the arch-independent memory model. Andrew's suggestion seems reasonable to me once the section mess is figured out. -- Mel Gorman SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx133.postini.com [74.125.245.133]) by kanga.kvack.org (Postfix) with SMTP id 74B196B0071 for ; Wed, 4 Jul 2012 05:20:15 -0400 (EDT) Date: Wed, 4 Jul 2012 10:20:06 +0100 From: Mel Gorman Subject: Re: [PATCH] mm: setup pageblock_order before it's used by sparse Message-ID: <20120704092006.GH14154@suse.de> References: <1341047274-5616-1-git-send-email-jiang.liu@huawei.com> <20120703140705.af23d4d3.akpm@linux-foundation.org> <4FF39F0E.4070300@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <4FF39F0E.4070300@huawei.com> Sender: owner-linux-mm@kvack.org List-ID: To: Jiang Liu Cc: Andrew Morton , Tony Luck , Yinghai Lu , Xishi Qiu , KAMEZAWA Hiroyuki , KOSAKI Motohiro , David Rientjes , Minchan Kim , Keping Chen , linux-mm@kvack.org, stable@vger.kernel.org, linux-kernel@vger.kernel.org, Jiang Liu On Wed, Jul 04, 2012 at 09:40:30AM +0800, Jiang Liu wrote: > > It's a bit ugly calling set_pageblock_order() from both sparse_init() > > and from free_area_init_core(). Can we find a single place from which > > to call it? It looks like here: > > > > --- a/init/main.c~a > > +++ a/init/main.c > > @@ -514,6 +514,7 @@ asmlinkage void __init start_kernel(void > > __stop___param - __start___param, > > -1, -1, &unknown_bootoption); > > > > + set_pageblock_order(); > > jump_label_init(); > > > > /* > > > > would do the trick? > > > > (free_area_init_core is __paging_init and set_pageblock_order() is > > __init. I'm too lazy to work out if that's wrong) > > Hi Andrew, > Thanks for you comments. Yes, this's an issue. > And we are trying to find a way to setup pageorder_block as > early as possible. Yinghai has suggested a good way for IA64, > but we still need help from PPC experts because PPC has the > same issue and I'm not familiar with PPC architecture. > We will submit another patch once we find an acceptable > solution here. I think it's overkill to try and do this on a per-architecture basis unless you are aware of a case where the per-architecture code cares about the value of pageblock_order. I find it implausible that the architecture needs to know the value very early in boot as pageblock_order is part of the arch-independent memory model. Andrew's suggestion seems reasonable to me once the section mess is figured out. -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org