From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Cooper Subject: Re: Xen BUG at page_alloc.c:1738 (Xen 4.5) Date: Tue, 19 May 2015 19:16:36 +0100 Message-ID: <555B7E04.5060300@citrix.com> References: <555B7BB8.90909@mhtx.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <555B7BB8.90909@mhtx.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Major Hayden , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 19/05/15 19:06, Major Hayden wrote: > Hello there, > > I've been doing some testing of Xen 4.5 on Fedora 22 (due out within a week) and I have an error that prevents the server from booting in the very early boot process: > >> (XEN) Xen call trace: >> (XEN) [] free_domheap_pages+0x240/0x430 >> (XEN) [] mmio_ro_do_page_fault+0x114/0x160 >> (XEN) [] do_page_fault+0x1a0/0x4f0 >> (XEN) [] handle_exception_saved+0x2e/0x6c >> (XEN) >> (XEN) >> (XEN) **************************************** >> (XEN) Panic on CPU 0: >> (XEN) Xen BUG at page_alloc.c:1738 >> (XEN) **************************************** > The full output is over in a Github Gist[1]. > > I've tested this on some physical machines (Dell, HP, and SuperMicro servers) as well as within a KVM virtual machine but I get the same boot error each time. It occurs with Xen 4.5 and Linux 3.17-4.0.x. Xen 4.5.1-rc1 fails in the same way. I've opened a Red Hat Bug[2] as well as a Xen bug[3] on it. > > The code within free_domheap_pages() hasn't changed much since late 2014 so I'm not sure if that's the culprit. Does anyone have any suggestions on how to debug it further? > > Thanks in advance! > > [1] https://gist.github.com/major/baa0e2eee7de51a2bcd1 > [2] https://bugzilla.redhat.com/show_bug.cgi?id=1219197 > [3] http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=1908 Can you try a debug hypervisor and rerun, to confirm the stack trace and see whether any assertions fire. Can you identify exactly which line xen/common/page_alloc.c:1738 is in your source? ~Andrew