From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Luming Yu" Date: Fri, 13 Jun 2008 16:22:10 +0000 Subject: Re: kdump regression: /proc/vmcore is 0 after kdump Message-Id: <3877989d0806130922p1f36a3bes9914144ac8c42266@mail.gmail.com> List-Id: References: <3877989d0806050058u3159e7b5x3113f63b3e0f3d8f@mail.gmail.com> <20080605081633.GA6713@verge.net.au> In-Reply-To: <20080605081633.GA6713@verge.net.au> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Simon Horman Cc: Petr Tesarik , linux-ia64@vger.kernel.org, Kexec Mailing List , Roland McGrath 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.. Thanks, Luming