Re: [Xen-devel] pv 2.6.31 (kernel.org) and save/migrate, domU BUG()

[Pasi Kärkkäinen <pasik@xxxxxx>]

On Sun, Nov 08, 2009 at 07:29:58AM -0800, Dan Magenheimer wrote:
> > > > > machine and it fails to save also.  Are you able to save
> > > > > 2.6.31{,.5} successfully?  On latest xen-unstable?
> > > > > (NOTE: Yes, I do have CONFIG_XEN_SAVE_RESTORE=y... don't
> > > > > know if that is important.)
> > 
> > Ok. I just tried with a Fedora 12 (rawhide) PV guest. I was able to 
> > "xm save" and "xm restore" it without problems. 
> > 
> > But I noticed there was a BUG printed on the guest console:
> > http://pasik.reaktio.net/xen/debug/dmesg-2.6.31.5-122.fc12.x86
> > _64-saverestore.txt
> > BUG: sleeping function called from invalid context at 
> > kernel/mutex.c:94
> > in_atomic(): 0, irqs_disabled(): 1, pid: 1052, name: kstop/0
> > Pid: 1052, comm: kstop/0 Not tainted 2.6.31.5-122.fc12.x86_64 #1
> 
> Ok, so it appears there is something problematic with
> saving an upstream kernel.  It might be (partially) fixed
> in Fedora 12 or maybe there is some other environmental
> difference which makes save fail entirely on my system.
> 

Yeah, fedora kernel has some patches, but it should be pretty 
close to upstream kernel..

btw was your guest UP or SMP? Mine was UP..

> > > The results explain why I can get it to run on
> > > one machine (an older laptop) and not run on another
> > > machine (a Nehalem system)... looks like this is maybe
> > > related to the cpuid-extended-topology-leaf bug that Jeremy
> > > sent a fix for upstream recently.
> > 
> > Did you try with that patch applied? 
> 
> No, the patch wasn't posted, just a pull request to Linus,
> so I don't have the patch (and am not a git expert so
> am not sure how to get it).
> 
> http://lists.xensource.com/archives/html/xen-devel/2009-11/msg00182.html
> 
> So I'll try it again when .6 or .7 is available.

See here for changelog:
http://git.kernel.org/?p=linux/kernel/git/jeremy/xen.git;a=shortlog;h=bugfix

You can get the diffs/patches from there using the links..

-- Pasi


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel