From mboxrd@z Thu Jan  1 00:00:00 1970
From: Randy Dunlap <randy.dunlap-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Subject: Re: [Bug #10872] x86_64 boot hang when CONFIG_NUMA=n
Date: Mon, 7 Jul 2008 22:28:29 -0700
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To: Yinghai Lu <yhlu.kernel-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: lkml <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>, Ingo Molnar <mingo-X9Un+BFzKDI@public.gmane.org>, Linus Torvalds <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, "Rafael J. Wysocki" <rjw-KKrjLPT3xs0@public.gmane.org>, Kernel Testers List <kernel-testers-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>

On Mon, 7 Jul 2008 17:24:16 -0700 Yinghai Lu wrote:

> On Mon, Jul 7, 2008 at 3:40 PM, Randy Dunlap <randy.dunlap-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org> wrote:
> > On Mon, 7 Jul 2008 11:39:17 -0700 Randy Dunlap wrote:
> >
> >> On Mon, 7 Jul 2008 08:32:18 +0200 Ingo Molnar wrote:
> >>
> >> >
> >> > * Linus Torvalds <torvalds-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org> wrote:
> >> >
> >> > > > This still happens with 2.6.26-rc9.  Using CONFIG_NUMA=y boots OK.
> >> > >
> >> > > Ok, then it wasn't the nr_zones thing.
> >> > >
> >> > > Since it seems to be repeatable for you, can you bisect it?
> >> >
> >> > one guess would be:
> >> >
> >> > | commit e8ee6f0ae5cd860e8e6c02807edfa3c1fa01bcb5
> >> > | Author: Yinghai Lu <yhlu.kernel-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> >> > | Date:   Sun Apr 13 01:41:58 2008 -0700
> >> > |
> >> > |     x86: work around io allocation overlap of HT links
> >> >
> >> > but ... since CONFIG_NUMA makes it work, i'm not sure about that.
> >> >
> >> > Randy, could you post the full CONFIG_NUMA bootlog as well, does it show
> >> > any difference in resource allocations?
> >>
> >> Good and bad boot logs are attached.  There are several differences, but I don't
> >> see any that are significant.
> >>
> >> I've started bisecting with:
> >>
> >> $ git bisect start
> >> $ git bisect bad v2.6.26-rc1
> >> $ git bisect good v2.6.25
> >>
> >> That's only about 1.29M lines of changes.
> >
> > git bisect and normal rebooting did not find a problem.
> >
> > I'll repeat this using kexec to boot the new kernel and see if that
> > locates any issues... since I normally use kexec to load/test new kernels
> > and that was how the failure occurred (occurs).
> >
> 
> same NON-NUMA kernel kexec NON-NUMA kernel?
> 
> or other kernel kexex it?

Ah.  Good question.  I hadn't noticed that.
NUMA kernel kexec-ing a non-NUMA kernel now fails, but it worked in 2.6.25.

---
~Randy
Linux Plumbers Conference, 17-19 September 2008, Portland, Oregon USA
http://linuxplumbersconf.org/