reboot/kexec in 2.6.38

reboot/kexec in 2.6.38

[Pavel Machek]

Hi!

I got report that  reboot/kexec does not work in recent kernels.

I tried both kexec and reboot in 2.6.38, and it worked ok. Maybe
config issue?
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

reboot/kexec in 2.6.38

[Eric Miao]

On Thu, Mar 17, 2011 at 2:45 PM, Pavel Machek <pavel@ucw.cz> wrote:
> Hi!
>
> I got report that ?reboot/kexec does not work in recent kernels.
>
> I tried both kexec and reboot in 2.6.38, and it worked ok. Maybe
> config issue?

I think it's config issue. Never heard of this.

> ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Pavel
> --
> (english) http://www.livejournal.com/~pavelmachek
> (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
>

reboot/kexec in 2.6.38

[Cyril Hrubis]

Hi!
> > I got report that ?reboot/kexec does not work in recent kernels.
> >
> > I tried both kexec and reboot in 2.6.38, and it worked ok. Maybe
> > config issue?
> 
> I think it's config issue. Never heard of this.
>

I've seen that on my zaurus a month or two ago. When kexeced to pxa-linux-2.6
then tried to kexec again. The last thing I've seen was Bye on the framebuffer
console and the machine freezed.

-- 
metan 

reboot/kexec in 2.6.38

[Eric W. Biederman]

Cyril Hrubis <metan@ucw.cz> writes:

> Hi!
>> > I got report that ?reboot/kexec does not work in recent kernels.
>> >
>> > I tried both kexec and reboot in 2.6.38, and it worked ok. Maybe
>> > config issue?
>> 
>> I think it's config issue. Never heard of this.
>>
>
> I've seen that on my zaurus a month or two ago. When kexeced to pxa-linux-2.6
> then tried to kexec again. The last thing I've seen was Bye on the framebuffer
> console and the machine freezed.

The basic kexec code has been stable and solid for a long time so kexec
failures are almost always hardware interaction problems.

Someone not stopping dma, or someone not putting the hardware in a state
that the next kernel can figure out how to initialize it.

Eric

reboot/kexec in 2.6.38

[Cyril Hrubis]

Hi!
> I think it's config issue. Never heard of this.

I've just compiled and booted 2.6.38. The kernel boots without problems when
flashed in. But I've had no success with kexec, the last lines I see are:

Starting new kernel
Bye!
_

Any ides where to dig?

-- 
metan

reboot/kexec in 2.6.38

[Eric W. Biederman]

Cyril Hrubis <metan@ucw.cz> writes:

> Hi!
>> I think it's config issue. Never heard of this.
>
> I've just compiled and booted 2.6.38. The kernel boots without problems when
> flashed in. But I've had no success with kexec, the last lines I see are:
>
> Starting new kernel

Enable early_printk to a serial port if you can.

There is definitely an issue in 2.6.38 where kdump doesn't work, that
right now looks like a memblock issue.

Eric

reboot/kexec in 2.6.38

[Cyril Hrubis]

Hi!
> >> I think it's config issue. Never heard of this.
> >
> > I've just compiled and booted 2.6.38. The kernel boots without problems when
> > flashed in. But I've had no success with kexec, the last lines I see are:
> >
> > Starting new kernel
> 
> Enable early_printk to a serial port if you can.
> 
> There is definitely an issue in 2.6.38 where kdump doesn't work, that
> right now looks like a memblock issue.

Finaly got time to solder serial adapter...

And now, after I configured kernel to print to both ttyS0 serial console and
tty0 the kexec started to work.

-- 
metan

reboot/kexec in 2.6.38

[Eric Miao]

On Tue, Apr 12, 2011 at 10:43 PM, Cyril Hrubis <metan@ucw.cz> wrote:
> Hi!
>> >> I think it's config issue. Never heard of this.
>> >
>> > I've just compiled and booted 2.6.38. The kernel boots without problems when
>> > flashed in. But I've had no success with kexec, the last lines I see are:
>> >
>> > Starting new kernel
>>
>> Enable early_printk to a serial port if you can.
>>
>> There is definitely an issue in 2.6.38 where kdump doesn't work, that
>> right now looks like a memblock issue.
>
> Finaly got time to solder serial adapter...
>
> And now, after I configured kernel to print to both ttyS0 serial console and
> tty0 the kexec started to work.

Cool. Please help check why it didn't work, and see if we have something
broken.

>
> --
> metan
>

reboot/kexec in 2.6.38

[Cyril Hrubis]

Hi!
> >> Enable early_printk to a serial port if you can.
> >>
> >> There is definitely an issue in 2.6.38 where kdump doesn't work, that
> >> right now looks like a memblock issue.
> >
> > Finaly got time to solder serial adapter...
> >
> > And now, after I configured kernel to print to both ttyS0 serial console and
> > tty0 the kexec started to work.
> 
> Cool. Please help check why it didn't work, and see if we have something
> broken.

Hmm, It seems to work now (I've changed the config slightly meanwhile and now
I've been unable to trigger the bug).

Note to myself: save configs that trigger strange behavior.

-- 
metan