From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761580AbYDPTSb (ORCPT ); Wed, 16 Apr 2008 15:18:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751308AbYDPTSX (ORCPT ); Wed, 16 Apr 2008 15:18:23 -0400 Received: from saeurebad.de ([85.214.36.134]:42233 "EHLO saeurebad.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751303AbYDPTSX (ORCPT ); Wed, 16 Apr 2008 15:18:23 -0400 From: Johannes Weiner To: Ingo Molnar Cc: Yinghai Lu , LKML , Linux MM , Andi Kleen , Yasunori Goto , KAMEZAWA Hiroyuki , Christoph Lameter , Andrew Morton , "Siddha\, Suresh B" Subject: Re: [RFC][patch 2/5] mm: Node-setup agnostic free_bootmem() References: <20080416113629.947746497@skyscraper.fehenstaub.lan> <20080416113719.092060936@skyscraper.fehenstaub.lan> <86802c440804161054h6f0cfc3dmde49006afb7889b2@mail.gmail.com> <86802c440804161144id4f2a68i37513ac0428c693@mail.gmail.com> <20080416184816.GA4400@elte.hu> Date: Wed, 16 Apr 2008 21:17:58 +0200 In-Reply-To: <20080416184816.GA4400@elte.hu> (Ingo Molnar's message of "Wed, 16 Apr 2008 20:48:16 +0200") Message-ID: <877iexfw2h.fsf@saeurebad.de> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.60 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.1.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Ingo Molnar writes: > * Yinghai Lu wrote: > >> > Yes, it should work well with cross nodes case. >> > >> > but please add boundary check on free_bootmem_node too. >> >> also please note: it will have problem span nodes box. >> >> for example: node 0: 0-2g, 4-6g, node1: 2-4g, 6-8g. and if ramdisk sit >> creoss 2G boundary. you will only free the range before 2g. > > yes. Such systems _will_ become more common - so the "this is rare" > arguments are incorrect. bootmem has to be robust enough to deal with > it. Ingo, I never doubted any of this, I was just asking more than once if and when this might happen. And I don't want the allocator become fragile, just not completely ignorant about bogus input. But the situation is still not clear for me. Ingo, how are these node spanning pfn ranges represented in the kernel? How many node descriptors will you have in the case Yinghai described and how will they look like? Hannes From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [RFC][patch 2/5] mm: Node-setup agnostic free_bootmem() References: <20080416113629.947746497@skyscraper.fehenstaub.lan> <20080416113719.092060936@skyscraper.fehenstaub.lan> <86802c440804161054h6f0cfc3dmde49006afb7889b2@mail.gmail.com> <86802c440804161144id4f2a68i37513ac0428c693@mail.gmail.com> <20080416184816.GA4400@elte.hu> Date: Wed, 16 Apr 2008 21:17:58 +0200 In-Reply-To: <20080416184816.GA4400@elte.hu> (Ingo Molnar's message of "Wed, 16 Apr 2008 20:48:16 +0200") Message-ID: <877iexfw2h.fsf@saeurebad.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: Ingo Molnar Cc: Yinghai Lu , LKML , Linux MM , Andi Kleen , Yasunori Goto , KAMEZAWA Hiroyuki , Christoph Lameter , Andrew Morton , "Siddha, Suresh B" List-ID: Hi, Ingo Molnar writes: > * Yinghai Lu wrote: > >> > Yes, it should work well with cross nodes case. >> > >> > but please add boundary check on free_bootmem_node too. >> >> also please note: it will have problem span nodes box. >> >> for example: node 0: 0-2g, 4-6g, node1: 2-4g, 6-8g. and if ramdisk sit >> creoss 2G boundary. you will only free the range before 2g. > > yes. Such systems _will_ become more common - so the "this is rare" > arguments are incorrect. bootmem has to be robust enough to deal with > it. Ingo, I never doubted any of this, I was just asking more than once if and when this might happen. And I don't want the allocator become fragile, just not completely ignorant about bogus input. But the situation is still not clear for me. Ingo, how are these node spanning pfn ranges represented in the kernel? How many node descriptors will you have in the case Yinghai described and how will they look like? Hannes -- 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