Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932891Ab3CUHXN (ORCPT ); Thu, 21 Mar 2013 03:23:13 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:51358 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757816Ab3CUHXL (ORCPT ); Thu, 21 Mar 2013 03:23:11 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: HATAYAMA Daisuke Cc: vgoyal@redhat.com, cpw@sgi.com, kumagai-atsushi@mxc.nes.nec.co.jp, lisa.mitchell@hp.com, heiko.carstens@de.ibm.com, akpm@linux-foundation.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, zhangyanfei@cn.fujitsu.com References: <87txo5bxk4.fsf@xmission.com> <20130321.122501.82758179.d.hatayama@jp.fujitsu.com> <8738vp75cy.fsf@xmission.com> <20130321.151428.393714972.d.hatayama@jp.fujitsu.com> Date: Thu, 21 Mar 2013 00:22:59 -0700 In-Reply-To: <20130321.151428.393714972.d.hatayama@jp.fujitsu.com> (HATAYAMA Daisuke's message of "Thu, 21 Mar 2013 15:14:28 +0900 (JST)") Message-ID: <87y5dhw71o.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-AID: U2FsdGVkX1+CegGRvZ1IcDtKGvxq+Ats6It0oOoPgMI= X-SA-Exim-Connect-IP: 98.207.154.105 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.1 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -3.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa05 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_04 7+ unique symbols in subject * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_03 6+ unique symbols in subject * 0.0 T_TooManySym_02 5+ unique symbols in subject X-Spam-DCC: XMission; sa05 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;HATAYAMA Daisuke X-Spam-Relay-Country: Subject: Re: [PATCH v3 18/21] vmcore: check if vmcore objects satify mmap()'s page-size boundary requirement X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Wed, 14 Nov 2012 14:26:46 -0700) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 990 Lines: 24 HATAYAMA Daisuke writes: > OK, rigorously, suceess or faliure of the requested free pages > allocation depends on actual memory layout at the 2nd kernel boot. To > increase the possibility of allocating memory, we have no method but > reserve more memory for the 2nd kernel now. Good enough. If there are fragmentation issues that cause allocation problems on larger boxes we can use vmalloc and remap_vmalloc_range, but we certainly don't need to start there. Especialy as for most 8 or 16 core boxes we are talking about a 4KiB or an 8KiBP allocation. Aka order 0 or order 1. Adding more memory is also useful. It is important in general to keep the amount of memory needed for the kdump kernel low. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/