Re: [REGRESSION][BISECTED][X86] next-20080526 hangs on boot

["Cyrill Gorcunov" <gorcunov@gmail.com>]

Hi,
thanks a lot for checking this!
I'll take a look today evening.

On 5/28/08, Adrian Bunk <bunk@kernel.org> wrote:
> On Tue, May 27, 2008 at 10:35:43AM +0400, Cyrill Gorcunov wrote:
>> On 5/26/08, Sitsofe Wheeler <sitsofe@yahoo.com> wrote:
>> > <posted & mailed>
>> >
>> > Sitsofe Wheeler wrote:
>> >
>> > > Cyrill Gorcunov wrote:
>> > >
>> > >> [Sitsofe Wheeler - Mon, May 26, 2008 at 03:04:54PM +0100]
>> > >> | When using a 32 bit linux-next-20080526 the bootup process will
>> > >> hang at
>> > >> | a random point (not even sysrq helps) with no additional output on
>> > >> the
>> > >> | screen (whereas linux-next-20080523 did boot). Mysteriously,
>> > >> booting
>> > >> | with nmi_watchdog=2 allows the boot to finish (booting with
>> > >> | nmi_watchdog=1 still stalls). I have bisected it down to commit
>> > >> | [d1b946b97d71423f365fa797d1428e1847c0bec1]:
>> > >>
>> > >> Hi, so it helps by reverting only that commit? I mean all further
>> > >> commits
>> > >> are still appiled?
>> > >
>> > > Ah that I hadn't tested. I believe I might need to revert
>> > > 4b82b277707a39b97271439c475f186f63ec4692 too if later commits are
>> > > applied
>> > > (but I'm still testing)
>> > >
>> > >> and, btw, could you post your config, please?
>> > >
>> > > http://sucs.org/~sits/test/config-20080526.txt
>> >
>> > OK applying the following patch (which is more or less a revert of
>> > [4b82b277707a39b97271439c475f186f63ec4692]) resolves the problem:
>>...
>>
>> Hi Sitsofe, actually I can't imagine how this revert have helped you
>> from hang. Newly introduced nmi_watchdog_default() didn't change
>> the logic of the code being used before this merge-series.
>>
>> Thomas, Ingo, maybe I've overlooked something (hard to believe ;)?
>> Only the change is the adding of new call for nmi_watchdog_default()
>> which was say 'inlined' before.
>>...
>
> arch/x86/kernel/smpboot.c:native_smp_prepare_cpus() also calls
> the no longer empty nmi_watchdog_default() on 32bit.
>
> cu
> Adrian
>
> --
>
>        "Is there not promise of rain?" Ling Tan asked suddenly out
>         of the darkness. There had been need of rain for many days.
>        "Only a promise," Lao Er said.
>                                        Pearl S. Buck - Dragon Seed
>
>