From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id 5A4E16B004D for ; Tue, 18 Aug 2009 04:27:45 -0400 (EDT) Received: from m1.gw.fujitsu.co.jp ([10.0.50.71]) by fgwmail6.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n7I8Rp97005731 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Tue, 18 Aug 2009 17:27:51 +0900 Received: from smail (m1 [127.0.0.1]) by outgoing.m1.gw.fujitsu.co.jp (Postfix) with ESMTP id 0FBA545DE56 for ; Tue, 18 Aug 2009 17:27:51 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (s1.gw.fujitsu.co.jp [10.0.50.91]) by m1.gw.fujitsu.co.jp (Postfix) with ESMTP id E172145DE4F for ; Tue, 18 Aug 2009 17:27:50 +0900 (JST) Received: from s1.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id B97B5E08004 for ; Tue, 18 Aug 2009 17:27:50 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s1.gw.fujitsu.co.jp (Postfix) with ESMTP id 28947E08006 for ; Tue, 18 Aug 2009 17:27:50 +0900 (JST) Date: Tue, 18 Aug 2009 17:25:52 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [Patch 8/8] kexec: allow to shrink reserved memory Message-Id: <20090818172552.779d0768.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <4A8A4ABB.70003@redhat.com> References: <20090812081731.5757.25254.sendpatchset@localhost.localdomain> <20090812081906.5757.39417.sendpatchset@localhost.localdomain> <4A83893D.50707@redhat.com> <4A83CD84.8040609@redhat.com> <4A8927DD.6060209@redhat.com> <20090818092939.2efbe158.kamezawa.hiroyu@jp.fujitsu.com> <4A8A4ABB.70003@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Amerigo Wang Cc: "Eric W. Biederman" , linux-kernel@vger.kernel.org, tony.luck@intel.com, linux-ia64@vger.kernel.org, linux-mm@kvack.org, Neil Horman , Andi Kleen , akpm@linux-foundation.org, bernhard.walle@gmx.de, Fenghua Yu , Ingo Molnar , Anton Vorontsov List-ID: On Tue, 18 Aug 2009 14:31:23 +0800 Amerigo Wang wrote: > Hi, thank you! > > Can I have a question ? > > > > - How crash kernel's memory is preserved at boot ? > > > > Use bootmem, I think. > I see. In x86, setup_arch() -> reserve_crashkernel() -> find_and_reserve_crashkernel() -> reserve_bootmem_generic() Then, all "active range" is already registered and there are memmap. > > It's hidden from the system before mem_init() ? > > > > Not sure, but probably yes. It is reserved in setup_arch() which is > before mm_init() which calls mem_init(). > > Do you have any advice to free that reserved memory after boot? :) > Let's see arch/x86/mm/init.c::free_initmem() Maybe it's all you want. - ClearPageReserved() - init_page_count() - free_page() - totalram_pages++ But it has no argumetns. Maybe you need your own function or modification. online_pages() does very similar. But, hmm,.. writing something open coded one for crashkernel is not very bad, I think. Thanks, -Kame -- 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