From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from tyo200.gate.nec.co.jp ([210.143.35.50]) by pentafluge.infradead.org with esmtp (Exim 4.63 #1 (Red Hat Linux)) id 1If9lb-0003EH-4B for kexec@lists.infradead.org; Tue, 09 Oct 2007 08:44:39 +0100 Received: from tyo201.gate.nec.co.jp ([10.7.69.201]) by tyo200.gate.nec.co.jp (8.13.8/8.13.4) with ESMTP id l997gRMo017196 for ; Tue, 9 Oct 2007 16:42:27 +0900 (JST) Message-ID: <470B3008.9040003@ah.jp.nec.com> Date: Tue, 09 Oct 2007 16:38:48 +0900 From: Takenori Nagano MIME-Version: 1.0 Subject: Re: [PATCH 0/2] add new notifier function References: <4704D09D.6080503@ah.jp.nec.com> In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces@lists.infradead.org To: "Eric W. Biederman" Cc: k-miyoshi@cb.jp.nec.com, Bernhard Walle , kdb@oss.sgi.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, vgoyal@in.ibm.com, Keith Owens , Andrew Morton Eric W. Biederman wrote: > Takenori Nagano writes: > >> Hi, >> >> These patches add new notifier function and implement it to panic_notifier_list. >> We used the hardcoded notifier chain so far, but it was not flexible. New >> notifier is very flexible, because user can change a list of order by debugfs. > > How is the lack of flexibility a problem? > Specifics please. Please read this again. http://www.gossamer-threads.com/lists/linux/kernel/797220?do=post_view_threaded#797220 Keith Owen said, > My stance is that _all_ the RAS tools (kdb, kgdb, nlkd, netdump, lkcd, > crash, kdump etc.) should be using a common interface that safely puts > the entire system in a stopped state and saves the state of each cpu. > Then each tool can do what it likes, instead of every RAS tool doing > its own thing and they all conflict with each other, which is why this > thread started. > > It is not the kernel's job to decide which RAS tool runs first, second > etc., it is the user's decision to set that policy. Different sites > will want different orders, some will say "go straight to kdump", other > sites will want to invoke a debugger first. Sites must be able to > define that policy, but we hard code the policy into the kernel. I agreed with him and I made new notifier function. > > My impression is that the purpose of this patchset is to build > infrastructure to sort out a conflict between kdb and the kexec code, > which it does not do, and it can not do if it does not own up to > it's real purpose. My motivation does not change. But I don't think kdump have to use notifer. I want to resolve this adopting the way which satisfy all users. Thanks, Takenori Nagano _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754238AbXJIHmv (ORCPT ); Tue, 9 Oct 2007 03:42:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752988AbXJIHmm (ORCPT ); Tue, 9 Oct 2007 03:42:42 -0400 Received: from TYO201.gate.nec.co.jp ([202.32.8.193]:61016 "EHLO tyo201.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752743AbXJIHml (ORCPT ); Tue, 9 Oct 2007 03:42:41 -0400 Message-ID: <470B3008.9040003@ah.jp.nec.com> Date: Tue, 09 Oct 2007 16:38:48 +0900 From: Takenori Nagano User-Agent: Thunderbird 2.0.0.6 (Windows/20070728) MIME-Version: 1.0 To: "Eric W. Biederman" CC: linux-kernel@vger.kernel.org, vgoyal@in.ibm.com, k-miyoshi@cb.jp.nec.com, kexec@lists.infradead.org, Bernhard Walle , Keith Owens , Andrew Morton , kdb@oss.sgi.com Subject: Re: [PATCH 0/2] add new notifier function References: <4704D09D.6080503@ah.jp.nec.com> In-Reply-To: Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Eric W. Biederman wrote: > Takenori Nagano writes: > >> Hi, >> >> These patches add new notifier function and implement it to panic_notifier_list. >> We used the hardcoded notifier chain so far, but it was not flexible. New >> notifier is very flexible, because user can change a list of order by debugfs. > > How is the lack of flexibility a problem? > Specifics please. Please read this again. http://www.gossamer-threads.com/lists/linux/kernel/797220?do=post_view_threaded#797220 Keith Owen said, > My stance is that _all_ the RAS tools (kdb, kgdb, nlkd, netdump, lkcd, > crash, kdump etc.) should be using a common interface that safely puts > the entire system in a stopped state and saves the state of each cpu. > Then each tool can do what it likes, instead of every RAS tool doing > its own thing and they all conflict with each other, which is why this > thread started. > > It is not the kernel's job to decide which RAS tool runs first, second > etc., it is the user's decision to set that policy. Different sites > will want different orders, some will say "go straight to kdump", other > sites will want to invoke a debugger first. Sites must be able to > define that policy, but we hard code the policy into the kernel. I agreed with him and I made new notifier function. > > My impression is that the purpose of this patchset is to build > infrastructure to sort out a conflict between kdb and the kexec code, > which it does not do, and it can not do if it does not own up to > it's real purpose. My motivation does not change. But I don't think kdump have to use notifer. I want to resolve this adopting the way which satisfy all users. Thanks, Takenori Nagano