Re: Crash during vmcore_init

From: Dave Young
Date: Thu Nov 17 2011 - 02:19:47 EST


On 11/17/2011 01:22 PM, Tim Hartrick wrote:

> Tejun, Dave,
>
> I will be happy to answer any questions about our environment or test
> debug or other patches. Just tell me what you need.


Thank you. Can you share your kernel config?

>
> tim
>
> On Nov 16, 2011 8:44 PM, "Dave Young" <dyoung@xxxxxxxxxx
> <mailto:dyoung@xxxxxxxxxx>> wrote:
>
> On 11/17/2011 12:34 PM, Tejun Heo wrote:
>
> > Hello,
> >
> > On Wed, Nov 16, 2011 at 7:30 PM, Dave Young <dyoung@xxxxxxxxxx
> <mailto:dyoung@xxxxxxxxxx>> wrote:
> >> This addr is converted to an invalid phys address,
> >
> > I'm a bit lost on the context here. Who's calling
> per_cpu_ptr_to_phys()?
>
>
> It's drivers/base/cpu.c : show_crash_notes()
>
> >
> >> looking the code below:
> >> if (in_first_chunk) {
> >> if (!is_vmalloc_addr(addr))
> >> return __pa(addr);
> >> else
> >> return page_to_phys(vmalloc_to_page(addr));
> >> } else
> >> return page_to_phys(pcpu_addr_to_page(addr));
> >>
> >> I dont understand per cpu allocation well, if addr is not in
> first chunk
> >> then it should be in vmalloc area?
> >
> > Yes, it is. First chunk can be embedded in the kernel linear address
> > space but from the second one, it's always set up from the top of the
> > vmalloc area with the same offset layout as the first chunk.
>
>
> in this case ffff880667c19ad0 fall out of vmalloc area and it's not in
> first chunk also.
>
> >
> >> Tejun, do you have any idea about this?
> >
> > Can you please tell me how to reproduce the problem? I'll try to find
> > out what's going on.
>
>
> make sure kernel support CRASH DUMP, then cat
> /sys/devices/system/cpu/cpu[x]/crash_notes
>
> Tim Hartrick <tim@xxxxxxxxxxxx <mailto:tim@xxxxxxxxxxxx>> reported
> the problem when test kdump.
> But I can not reproduce this. I think tim can help to test
>
> >
> > Thanks.
> >
>
>
>
> --
> Thanks
> Dave
>



--
Thanks
Dave
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