From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Luming Yu" Date: Sun, 15 Jun 2008 09:26:36 +0000 Subject: Re: kdump regression: /proc/vmcore is 0 after kdump Message-Id: <3877989d0806150226x62fc1d1bk96131430f55848e1@mail.gmail.com> List-Id: References: <3877989d0806050058u3159e7b5x3113f63b3e0f3d8f@mail.gmail.com> <20080605081633.GA6713@verge.net.au> <3877989d0806130922p1f36a3bes9914144ac8c42266@mail.gmail.com> In-Reply-To: <3877989d0806130922p1f36a3bes9914144ac8c42266@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: LKML , andrew.patterson@hp.com Cc: linux-ia64@vger.kernel.org, Petr Tesarik , Roland McGrath , Kexec Mailing List , Simon Horman On Sat, Jun 14, 2008 at 12:22 AM, Luming Yu wrote: > On Thu, Jun 5, 2008 at 4:16 PM, Simon Horman wrote: >> On Thu, Jun 05, 2008 at 03:58:40PM +0800, Luming Yu wrote: >>> On Tue, Jun 3, 2008 at 2:02 PM, Luming Yu wrote: >>> >> I'm trying upstream kdump to get more detailed data for help analysis >>> >> the scenario.. >>> > Upstream kdump doesn't work! don't know what cause the regression, >>> > possibly kexec-tools... >>> > Need investigation here! >>> > >>> >>> I tested mainline kernel from 2.6.20 to 2.6.26-rc4 on my tiger4.. >>> whatever I try, /proc/vmcore is always 0 ! >>> >>> Then I managed to get Nan hai's original patch against 2.6.19.. >>> http://marc.info/?l=linux-ia64&m6521104831321&w=2 >>> This patch doesn't have zero-vmcore problem. >>> >>> Given the age of the kdump feature and so many upstream releases since >>> 2.6.20, I'm in doubt why I don't see this kind of bug report on ia64 >>> mailing list before? >>> >>> PS. Now I can start to capture info for the strace problem with 2.6.19 >>> kernel +Nahai's 2.6.19 kdump patch, hope the problem is still >>> reproducible. >> >> Which version of kexec-tools are you using? >> If you haven't done so already, could you try the latest version, 20080324. >> >> http://www.eu.kernel.org/pub/linux/kernel/people/horms/kexec-tools/ >> > > Yes, this resolves one of my kdump problem. > But there seems to have a regression introduced into upstream probably > starting from 2.6.25. > The last kernel with kdump working on this box is 2.6.24. I don't have > time to start bisection to find out which patch causes that regression > right now.Maybe someone on this list can give me some hint.. My git bisection result indicates the following commit causes the kdump regression in 2.6.25-rc1: commit 3c75e23784e6ed5f4841de43d0750fd9b37bafcb Author: Andrew Patterson Date: Tue Jan 22 17:18:27 2008 -0700