Re: /proc/kcore has a unreasonable size(281474974617600) in x86_64 2.6.30-rc8.

Amerigo Wang
2009-06-05T07:54:40Z

On Fri, Jun 05, 2009 at 02:59:46PM +0800, Tao Ma wrote:
>
>
> Andrew Morton wrote:
>> On Fri, 05 Jun 2009 12:03:52 +0800 Tao Ma <tao.ma@oracle.com> wrote:
>>
>>> Hi list,
>>> In 2.6.30-rc8, /proc/kcore in x86_64's size is unreasonable
>>> large to be 281474974617600.
>>> While in a x86 box, it is 931131392 which looks sane.
>>>
>>> [root@test8 ~]# ll /proc/kcore
>>> -r-------- 1 root root 281474974617600 Jun 5 11:15 /proc/kcore
>>>
>>> [root@ocfs2-test9 ~]$ ll /proc/kcore
>>> -r-------- 1 root root 931131392 Jun 5 11:58 /proc/kcore
>>>
>>> I just noticed this when kexec fails in "Can't find kernel text map
>>> area from kcore".
>>>
>>> Is there something wrong?
>>>
>>
>> fs/proc/kcore.c hasn't changed since October last year. Was 2.6.29 OK?
>> Earlier kernels?
> with 2.6.29, ls shows the same output.
> [root@test8 ~]# ll /proc/kcore
> -r-------- 1 root root 281474974617600 Jun 5 14:35 /proc/kcore

Thanks.

It looks like the value of 'high_memory' is insane..

Can you get its value on your machine? You can add a printk() or use
systemtap etc..