Re: [crash, -git] NULL pointer dereference, IP: [<c0190884>] page_cgroup_zoneinfo+0xf/0x1b

[Li Zefan <lizf@cn.fujitsu.com>]

>>  nr of bisection commits: 14
>>  ----------------------------
>>  656eb2c: add CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS
>>  6409324: coredump: format_corename: don't append .%pid if  multi-threaded
>>  b747c8c: make ptrace_untrace() static
>>  c459643: bitmask: remove bitmap_scnprintf_len()
>>  30e8e13: cpuset: use seq_*mask_* to print masks
>>  3eda201: seq_file: add seq_cpumask_list(), seq_nodemask_list()
>>  85dd030: seq_file: don't call bitmap_scnprintf_len()
>>  40b6a76: cpuset.c: remove extra variable
>>  52d4b9a: memcg: allocate all page_cgroup at boot

The bug should be introduced by this patch.

>>  c05555b: memcg: atomic ops for page_cgroup->flags
>>  addb9ef: memcg: optimize per-cpu statistics
>>  5b4e655: memcg: avoid accounting special pages
>>  b7abea9: memcg: make page->mapping NULL before uncharge
>>  073e587: memcg: move charge swapin under lock
>>
>> i'll poke in the middle - maybe i'm lucky and can find a 
>> working/crashing tree to nudge the bisection back into life.
> 
> Hi, Ingo,
> 
> Li Zefan has reported this problem and Kamezawa is looking into it.

Yes, but seems a bit tough...

> I am unwell,
> I hope to look into the problem when I feel better or at-least in the intervals
> of time that I feel better.
>