Re: [Bug #11989] Suspend failure on NForce4-based boards due to chanes in stop_machine

[Dmitry Adamushko]

2008/11/10 Rafael J. Wysocki <rjw@xxxxxxx>:
> On Monday, 10 of November 2008, Rafael J. Wysocki wrote:
>> On Monday, 10 of November 2008, Heiko Carstens wrote:
>> > On Sun, Nov 09, 2008 at 06:59:16PM +0100, Rafael J. Wysocki wrote:
>> > > This message has been generated automatically as a part of a report
>> > > of recent regressions.
>> > >
>> > > The following bug entry is on the current list of known regressions
>> > > from 2.6.27.  Please verify if it still should be listed and let me know
>> > > (either way).
>> > >
>> > >
>> > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=11989
>> > > Subject           : Suspend failure on NForce4-based boards due to chanes in stop_machine
>> > > Submitter : Rafael J. Wysocki <rjw@xxxxxxx>
>> > > Date              : 2008-11-03 0:28 (7 days old)
>> > > First-Bad-Commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c9583e55fa2b08a230c549bd1e3c0bde6c50d9cc
>> > > References        : http://marc.info/?l=linux-kernel&m=122567187604356&w=4
>> >
>> > Hi Rafael,
>>
>> Hi,
>>
>> > could you provide more informations for this, please?
>> >
>> > What is your kernel configuration?
>>
>> Available at: http://www.sisk.pl/kernel/debug/mainline/2.6.28-rc3/kitty-config
>>
>> > Do you have any binary only modules (nvidia?) loaded?
>>
>> No, I don't.
>>
>> > Is it possible to recreate the bug by e.g. just doing something like
>> >
>> > echo 0 > /sys/devices/system/cpu/cpu1/online
>>
>> I haven't checked (yet), I'll do that later today and let you know.
>>
>> > (or any other online cpu)? Or does it trigger any lockdep warnings?
>
> It cannot be reproduced with offlining CPU1 and it doesn't trigger any
> warnings from lockdep.
>
> However, it is reproducible by doing
>
> # echo core > /sys/power/pm_test
>
> and repeating
>
> # echo disk > /sys/power/state
>
> for a couple of times, in which case the last two lines printed to the console
> before a (solid) hang are:
>
> SMP alternatives: switching to SMP code
> Booting processor 1 APIC 0x1 ip 0x6000
>
> So, it evidently fails while re-enabling the non-boot CPU and not during
> disabling it as I thought before.

Can you also provide the full log including the messages when a system
goes down please?

At first glance, "Botting processor..." as the last message looks
strange in this context.
So either wakeup_secondary_cpu()'s completion failed for some reason
(say, due to some kind of a problem that took place while disabling
non-boot cpus... I'm purely speculating here so far) or the printk's
output was not complete.

Perhaps, redoing the test with pr_debug() in arch/x86/kernel/smpboot.c
enabled would shed more light...


-- 
Best regards,
Dmitry Adamushko
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