crash-utility-bounces(a)redhat.com wrote on 02/22/2006 07:31:43 AM:
Rachita Kothiyal wrote:
>
> > Rachita Kothiyal wrote:
>
>
> >
> > This happens in get_idle_threads() when perusing the runqueues
array,
> > where each per-cpu runqueue data structure contains a
pointer to the
> > idle (swapper) task for that CPU. Now, this process requires that
the
> > per-cpu address manipulations are working correctly in
order to find
the
> > each cpu's runqueue data structure. It looks like the
ppc64 change
> > for per-cpu data accesses is suspect here:
> >
> > > Fix to recognize post-2.6.15 ppc64 kernels moving the
per_cpu_offsets
> > > to the "paca" structure. Without this
patch, crash fails with the
> > > following error messages: "crash: cannot determine idle task
addresses
> > > from init_tasks[] or runqueues[]" and
"crash: cannot resolve
> > > init_task_union". (pbadari(a)us.ibm.com)
> >
>
> Right, but I thought this patch fixed this problem.
> (I am using crash-4.0-2.21, and it includes this patch)
Right -- me too... ;-)
Badari tested his patch on live system. He can give more information
anyway.
However, I used his patch for testing PPC64 vmcore before I post my patch.
Did not see any issue when invoking crash tool. Tested on 2.6.16-rc2-gi9.
I will also verify if I have the same vmcore.
Thanks
Haren
>
>
> > >
> > > But I was able to run it ok on a live system.
> > >
> >
> > Same kernel? I have no idea why there would be a difference
> > between live and vmcore.
>
> Yes, same kernel (2.6.16-rc4)
>
I'm sure Badari can give you more information, but you might start
by putting some debug printf's in his new ppc64_paca_init() function
to see whether it's calculating the same kt->__per_cpu_offset[cpu]
values on a live system vs. its associated vmcore?
Dave
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