Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757523AbaKTRig (ORCPT ); Thu, 20 Nov 2014 12:38:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43928 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756223AbaKTRif (ORCPT ); Thu, 20 Nov 2014 12:38:35 -0500 Date: Thu, 20 Nov 2014 12:38:21 -0500 From: Dave Jones To: Vivek Goyal Cc: Don Zickus , Thomas Gleixner , Linus Torvalds , Linux Kernel , the arch/x86 maintainers , WANG Chao , Baoquan He , Dave Young Subject: Re: frequent lockups in 3.18rc4 Message-ID: <20141120173821.GB9550@redhat.com> Mail-Followup-To: Dave Jones , Vivek Goyal , Don Zickus , Thomas Gleixner , Linus Torvalds , Linux Kernel , the arch/x86 maintainers , WANG Chao , Baoquan He , Dave Young References: <20141118145234.GA7487@redhat.com> <20141118215540.GD35311@redhat.com> <20141118220254.GA2571@redhat.com> <20141119144105.GB108701@redhat.com> <20141119150333.GB2953@redhat.com> <20141119153852.GA16146@redhat.com> <20141119162806.GD2953@redhat.com> <20141120161055.GA8309@redhat.com> <20141120164809.GA22216@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141120164809.GA22216@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 20, 2014 at 11:48:09AM -0500, Vivek Goyal wrote: > Can we try following and retry and see if some additional messages show > up on console and help us narrow down the problem. > > - Enable verbose boot messages. CONFIG_X86_VERBOSE_BOOTUP=y > > - Enable early printk in second kernel. (earlyprintk=ttyS0,115200). > > You can either enable early printk in first kernel and reboot. That way > second kernel will automatically have it enabled. Or you can edit > "/etc/sysconfig/kdump" and append earlyprintk=<> to KDUMP_COMMANDLINE_APPEND. > You will need to restart kdump service after this. > > - Enable some debug output during runtime from kexec purgatory. For that one > needs to pass additional arguments to /sbin/kexec. You can edit > /etc/sysconfig/kdump file and modify "KEXEC_ARGS" to pass additional > arguments to /sbin/kexec during kernel load. I use following for my > serial console. > > KEXEC_ARGS="--console-serial --serial=0x3f8 --serial-baud=115200" > > You will need to restart kdump service. The only serial port on this machine is usb serial, which doesn't have io ports. >From my reading of the kexec man page, it doesn't look like I can tell it to use ttyUSB0. And because it relies on usb being initialized, this probably isn't going to help too much with early boot. earlyprintk=tty0 didn't show anything extra after the sysrq-c oops. likewise, =ttyUSB0 I'm going to try bisecting the problem I'm debugging again, so I'm not going to dig into this much more today. Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/