From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philippe Gerum In-Reply-To: <4C6ACA50.3080108@domain.hid> References: <4C45539B.70204@domain.hid> <4C6932E8.7050701@domain.hid> <4C694AB3.8050407@domain.hid> <4C698E16.5050806@domain.hid> <1282040830.1730.232.camel@domain.hid> <4C6ACA50.3080108@domain.hid> Content-Type: text/plain; charset="UTF-8" Date: Wed, 18 Aug 2010 10:27:29 +0200 Message-ID: <1282120049.1730.304.camel@domain.hid> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] kernel 2.6.32.11 with xenomai 2.5.3 fails to boot on ubuntu lucid system List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Kisdaroczi Cc: xenomai@xenomai.org, Jan Kiszka On Tue, 2010-08-17 at 19:43 +0200, Stefan Kisdaroczi wrote: > On 17.08.2010 12:27, Philippe Gerum wrote: > > On Mon, 2010-08-16 at 21:14 +0200, Theo Veenker wrote: > > > >> On 08/16/2010 04:26 PM, Theo Veenker wrote: > >> > >>> Gilles Chanteperdrix wrote: > >>> > >>>> Theo Veenker wrote: > >>>> > >>>>> Hi, > >>>>> > >>>>> I want to upgrade all our PC's from Ubuntu hardy to lucid and in the > >>>>> process > >>>>> I'm also going from kernel 2.6.29.5 with Xenomai 2.4.8 to kernel > >>>>> 2.6.32.11 > >>>>> with Xenomai 2.5.3. > >>>>> > >>>>> I first built and tested the 2.6.32.11 kernel with 2.5.3 on my hardy > >>>>> system > >>>>> and all went fine. But the problem is it just doesn't run on the > >>>>> lucid distro. > >>>>> > >>>> This, I do not understand, the kernel does not need any support from the > >>>> distribution for booting, how can the same kernel boot with one > >>>> distribution, and not with the other? When you say the "same kernel", do > >>>> you mean the exact same zImage or bzImage, or do you mean the kernel > >>>> with the same configuration, but with a different compiler, or only the > >>>> version is identical? > >>>> > >>>> > >>> It is a complete mystery to me either. I compiled my kernel into a deb > >>> package > >>> and installed the very same deb package on three machines: > >>> MSI p45 neo3 with Hardy on it -> works OK > >>> MSI p45 neo3 with Ludid on it -> nothing (works fine with regular kernel) > >>> MSI 945P with Lucid on it: -> nothing (works fine with regular kernel) > >>> > >>> I'll try the suggestions posted and keep you informed. > >>> > >> OK. Connected a terminal to catch early kernel messages. Still no output > >> unfortunately (with the regular kernel I do get output on the terminal, > >> so the connection works). > >> > >> Meanwhile also built and tested kernel 2.6.32.15 + xenomai 2.5.4. Still nothing. > >> I'm clueless. I'm running Xenomai for years on dozens of systems and I've > >> never run into problems like this. I think I'll have to sit down and take a > >> close look at what I'm doing. I've always built my kernels using make-kpkg, > >> maybe that somehow introduces a problem here. I'll try without it. > >> > >> (unfortunately/luckily I have to work from home for a few days so I can't > >> get to the test system until later this week) > >> > > I failed to reproduce the issue yet, but it very much looks like an > > I-pipe bug. Could you try the following config variants when time > > allows: > > > > I installed the kernel (2.6.32.15 2.5.4 x86 32bit) which is working on > my laptop in a kvm machine. > In the virtual machine the kernel never starts and hangs. > I attached gdb to kvm and according to the cpu registers and system.map > it hangs in 'doublefault_fn'. As I'm not really familiar with gdb i'm > thankful if someone has a hint how to proceed. Thanks If you could ask for a backtrace ("bt" command) in gdb once attached to the hanged kernel, and post the output there, that would be great. Meanwhile, I tried to reproduce the issue in kvm with no luck so far. Aside of timing issues making the boot over kvm quite shaky and most of the time impossible with the APIC enabled, using a legacy 8254 mode boots but never hangs. Pure emulation with -no-kvm or enabling kvm on the host does not make a difference. I've been trying with a 32bit guest over a 64bit host, and both host and guest in 32bit mode to no avail so far (QEMU PC emulator version 0.12.3 (qemu-kvm-0.12.3)). I had a bit more luck on real hw though; a m65 Dell workstation (core2 duo) seems to be kind enough to break during early boot. The failure ratio is variable, but 1 crash over 3-5 boots is common; sometimes it even crashes several times in a row. The bad news is that no rs232 is available from this machine, and the crash happens way to early to count on any usb<->serial converter to get any debug output; so this is going to take some time to nail down the bug on this hw. I don't expect netconsole to help me in any way either, for the same reason. Here are some more information I could get though: - CONFIG_SMP, CONFIG_*_APIC/IO_APIC do not make any difference. I still have a kernel crashing against the wall in plain, basic uniprocessor mode (i.e. 8254 legacy IRQ and timing). - The very same kernel image does not break when booted via tftp here. It really seems to need a boot of the kernel image from the hard drive to get the issue. However, having the rootfs over NFS or on the hdd does not seem to make any difference. This could be the sign of a mishandled early access fault, which would be confirmed by your trace showing that the double fault handler is called. - CONFIG_IPIPE introduces the issue alone; no need for CONFIG_XENOMAI. Since you are lucky enough to reproduce the bug over kvm, could you confirm my findings on your setup? i.e. that CONFIG_SMP, CONFIG_*APIC* and CONFIG_XENOMAI are not involved in this? PS: At this point, I think this bug only occurs in 32bit mode, but this has to be verified. TIA, -- Philippe.