From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]) by bombadil.infradead.org with esmtp (Exim 4.69 #1 (Red Hat Linux)) id 1MPAuZ-0002bw-7K for kexec@lists.infradead.org; Fri, 10 Jul 2009 07:52:58 +0000 Received: from m4.gw.fujitsu.co.jp ([10.0.50.74]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id n6A7qlbR024705 for (envelope-from seto.hidetoshi@jp.fujitsu.com); Fri, 10 Jul 2009 16:52:47 +0900 Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 7552545DE4D for ; Fri, 10 Jul 2009 16:52:46 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 5378945DE6E for ; Fri, 10 Jul 2009 16:52:46 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 370081DB8043 for ; Fri, 10 Jul 2009 16:52:46 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id BF80C1DB803B for ; Fri, 10 Jul 2009 16:52:45 +0900 (JST) Message-ID: <4A56F343.7040907@jp.fujitsu.com> Date: Fri, 10 Jul 2009 16:52:35 +0900 From: Hidetoshi Seto MIME-Version: 1.0 Subject: Re: [PATCH] kdump: Enable kdump if 2nd-kernel is loaded. References: <4A55A4AE.3000206@mxs.nes.nec.co.jp> <4A56E069.5040907@jp.fujitsu.com> <4A56E83B.50600@mxs.nes.nec.co.jp> In-Reply-To: <4A56E83B.50600@mxs.nes.nec.co.jp> 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+dwmw2=infradead.org@lists.infradead.org To: Ken'ichi Ohmichi Cc: kexec-ml , lkml Hi Ohmichi-san, Ken'ichi Ohmichi wrote: > Hidetoshi Seto wrote: >> I'd like to quote your comment: >> >>>> I tried to test a kdump on linux-2.6.31-rc1 *without* a kernel parameter >>>> "oops=panic" by `echo c > /proc/sysrq-trigger`, but a kdump did not work >>>> because a kdump, which is occurred by `echo c > /proc/sysrq-trigger`, has >>>> been changed to a NULL pointer error instead of calling crash_kexec() >>>> since linux-2.6.31-rc1. >> So the real problem is that kdump is not triggered by the NULL pointer oops >> if !panic_on_oops, isn't it? >> >> It seems that you should report this trouble of sysrq-c as a regression. > > I don't think this problem is a regression of sysrq-c. > This change of sysrq-c looks reasonable to me. Because sysrq-c is used > for the test of kdump, and its code path has been changed to the same > path as a kdump on oops (a real problem, not test). > So we can test a kdump by a real oops, that is good to me. > As a result, I could find this problem a kdump is not enabled without > "oops=panic". Still I believe this is a regression of sysrq-c. If required function of sysrq-c were "cause a real oops", then it is not regression. But as described in Documentation/sysrq.txt, real usage of sysrq-c is "perform a kexec reboot," i.e. kdump. So I think sysrq-c should use panic instead of oops if it want to kick the kdump unconditionally. However, yes, I agree it is a problem on the kdump's policy that kdump on oops is not enabled without the option. I'm not sure how much people want to enable kdump only on panic while not on oops, but I suppose it will be negligible. Or it would be better to introduce kdump_on_oops option or so. Thanks, H.Seto _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec