From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 1B42B8D003B for ; Mon, 25 Apr 2011 20:32:18 -0400 (EDT) Received: from m3.gw.fujitsu.co.jp (unknown [10.0.50.73]) by fgwmail5.fujitsu.co.jp (Postfix) with ESMTP id 1D9DD3EE0AE for ; Tue, 26 Apr 2011 09:32:15 +0900 (JST) Received: from smail (m3 [127.0.0.1]) by outgoing.m3.gw.fujitsu.co.jp (Postfix) with ESMTP id 04BD845DE95 for ; Tue, 26 Apr 2011 09:32:15 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (s3.gw.fujitsu.co.jp [10.0.50.93]) by m3.gw.fujitsu.co.jp (Postfix) with ESMTP id D0E0145DE93 for ; Tue, 26 Apr 2011 09:32:14 +0900 (JST) Received: from s3.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id C2363E08003 for ; Tue, 26 Apr 2011 09:32:14 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.240.81.133]) by s3.gw.fujitsu.co.jp (Postfix) with ESMTP id 7B94F1DB8038 for ; Tue, 26 Apr 2011 09:32:14 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH] convert parisc to sparsemem (was Re: [PATCH v3] mm: make expand_downwards symmetrical to expand_upwards) In-Reply-To: <1303583657.4116.11.camel@mulgrave.site> References: <1303507985.2590.47.camel@mulgrave.site> <1303583657.4116.11.camel@mulgrave.site> Message-Id: <20110426093328.F33D.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Date: Tue, 26 Apr 2011 09:32:13 +0900 (JST) Sender: owner-linux-mm@kvack.org List-ID: To: James Bottomley Cc: kosaki.motohiro@jp.fujitsu.com, Dave Hansen , Christoph Lameter , David Rientjes , Pekka Enberg , Michal Hocko , Andrew Morton , Hugh Dickins , linux-mm@kvack.org, LKML , linux-parisc@vger.kernel.org, Ingo Molnar , x86 maintainers , Tejun Heo , Mel Gorman Hi James, % make CROSS_COMPILE=hppa64-linux- ARCH=parisc CHK include/linux/version.h CHK include/generated/utsrelease.h CC arch/parisc/kernel/asm-offsets.s In file included from include/linux/topology.h:32:0, from include/linux/sched.h:78, from arch/parisc/kernel/asm-offsets.c:31: include/linux/mmzone.h:916:27: fatal error: asm/sparsemem.h: No such file or directory Parhaps, you forgot to quilt add? > This is the preliminary conversion. It's very nasty on parisc because > the memory allocation isn't symmetric anymore: under DISCONTIGMEM, we > push all memory into bootmem and then let free_all_bootmem() do the > magic for us; now we have to do separate initialisations for ranges > because SPARSEMEM can't do multi-range boot memory. It's also got the > horrible hack that I only use the first found range for bootmem. I'm > not sure if this is correct (it won't be if the first found range can be > under about 50MB because we'll run out of bootmem during boot) ... we > might have to sort the ranges and use the larges, but that will involve > us in even more hackery around the bootmem reservations code. > > The boot sequence got a few seconds slower because now all of the loops > over our pfn ranges actually have to skip through the holes (which takes > time for 64GB). > > All in all, I've not been very impressed with SPARSEMEM over > DISCONTIGMEM. It seems to have a lot of rough edges (necessitating > exception code) which DISCONTIGMEM just copes with. > > And before you say the code is smaller, that's because I converted us to > generic show_mem(). Cool! I hoped to remove arch specific show_mem() long time. And, nitpick comment. Could you please use #ifdef CONFIG_FLAGMEM instead #ifndef CONFIG_SPARSEMEM? MM gyes parse '#ifndef CONFIG_SPARSEMEM' as valid-both-flatmem-and-discontigmem. but this code isn't. If my quick grep is correct, all of your #ifndef SPARSEMEM can be converted #ifdef FALTMEM. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org