From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933251AbZHGTum (ORCPT ); Fri, 7 Aug 2009 15:50:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933212AbZHGTuk (ORCPT ); Fri, 7 Aug 2009 15:50:40 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:54505 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933202AbZHGTui (ORCPT ); Fri, 7 Aug 2009 15:50:38 -0400 To: Amerigo Wang Cc: Neil Horman , linux-kernel@vger.kernel.org, tony.luck@intel.com, linux-ia64@vger.kernel.org, akpm@linux-foundation.org, Ingo Molnar , Anton Vorontsov , Andi Kleen , Bernhard Walle , Kexec Mailing List References: <20090805112123.6552.73574.sendpatchset@localhost.localdomain> <20090805140408.GJ7259@hmsreliant.think-freely.org> <4A7A3A78.7080200@redhat.com> <4A7A506B.2060008@redhat.com> <4A7A70E5.2010204@redhat.com> <4A7A7A0F.6070906@redhat.com> <4A7A9E54.60705@redhat.com> From: ebiederm@xmission.com (Eric W. Biederman) Date: Fri, 07 Aug 2009 12:50:23 -0700 In-Reply-To: <4A7A9E54.60705@redhat.com> (Amerigo Wang's message of "Thu\, 06 Aug 2009 17\:11\:48 +0800") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Rcpt-To: amwang@redhat.com, kexec@lists.infradead.org, bernhard.walle@gmx.de, andi@firstfloor.org, avorontsov@ru.mvista.com, mingo@elte.hu, akpm@linux-foundation.org, linux-ia64@vger.kernel.org, tony.luck@intel.com, linux-kernel@vger.kernel.org, nhorman@redhat.com X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-DCC: XMission; sa01 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Amerigo Wang X-Spam-Relay-Country: X-Spam-Report: * -1.8 ALL_TRUSTED Passed through trusted hosts only via SMTP * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% * [score: 0.0000] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa01 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 XM_SPF_Neutral SPF-Neutral * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay Subject: Re: [Patch 0/7] Implement crashkernel=auto X-SA-Exim-Version: 4.2.1 (built Thu, 25 Oct 2007 00:26:12 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Let me put this concrete proposal on the table. The problem: With the current set of crashkernel= options we are asking the distribution installer to perform magic. Moving as much of this logic into a normal init script for better maintenance is desirable. My proposal: Implement crashkernel=max which reserves as much memory as is reasonable for a crash kernel, without seriously affecting stability, performance, and reliability. As an initial approximation I would use a 32nd of low memory. In addition implement: /sys/kernel/crash_size That can be written to (with enough privileges when no crash kernel is loaded) reduce the amount of memory reserved by the crash kernel. Bernhard does that sound useful to you? Amerigo does that seem reasonable? Eric