From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751940Ab1J0PIl (ORCPT ); Thu, 27 Oct 2011 11:08:41 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:30389 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751169Ab1J0PIk (ORCPT ); Thu, 27 Oct 2011 11:08:40 -0400 Date: Thu, 27 Oct 2011 11:08:26 -0400 From: Konrad Rzeszutek Wilk To: Miche Baker-Harvey Cc: Greg KH , linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com Subject: Re: Regression: patch " hvc_console: display printk messages on console." causing infinite loop with 3.2-rc0 + Xen. Message-ID: <20111027150826.GC1157@phenom.dumpdata.com> References: <20111027053007.GA32765@phenom.dumpdata.com> <20111027054806.GA1377@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: acsinet21.oracle.com [141.146.126.237] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090203.4EA973F3.0077:SCFMA922111,ss=1,re=-4.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 27, 2011 at 07:45:07AM -0700, Miche Baker-Harvey wrote: > Bummer. Sorry about that. > > Konrad, could you give me a hand figuring out what's up with this - I'm not > running Zen here. (If there's a test suite I could have run, mea culpa, and > please point me in the right direction.) I kind of run the nightly build/test rinse & repeat cycle using this: git://xenbits.xen.org/xentesttools/bootstrap.git But it might be just easier for you to install Fedora Core 16, do 'yum install xen', reboot, make sure you can boot Xen, and then build a 3.2 kernel with your patch + debug stuff. > > The "console [hvc0] enabled" message is coming from register_console() in > printk.c, and it doesn't have any loops. > It's called from hvc_console_init(), hvc_instantiate(), and hvc_alloc(), > none of which have loops. The call in hvc_alloc() is the one I added, so > either I've inadvertently made one of the other two repeat (I'm guestting > hvc_instantiate() is the one you're using), or you're infinitely calling > hvc_alloc(). There's a calls to hvc_alloc() in hvc_xen.c::xen_hvc_init(), > and in init_port_console() in virtio_console.c, but again, no loops. > Similarly for hvc_instantiate(). > > So, could I trouble you to put a breakpoint in register_console() and send > me the stack? A dump_stack() should suffice I presume? Yeah let me do that.