Re: [RFC Patch 1/2] kexec: show memory info in /proc/iomem

Amerigo Wang
2009-08-12T01:17:32Z

Eric W. Biederman wrote:
> Amerigo Wang <amwang@redhat.com> writes:
>
>
>> This patch implements showing kexec memory area via /proc/iomem.
>> For example, with this patch we can see:
>>
>> # cat /proc/iomem
>> ...
>> 00100000-7ffeffff : System RAM
>> 01000000-012e1424 : Kernel code
>> 012e1425-015f1aff : Kernel data
>> 0166b000-01b4b88f : Kernel bss
>> 02000000-083fffff : Crash kernel
>> 02000000-028fffff : Used
>> 02900000-083fffff : Unused
>> ...
>>
>> So that user can know how much memory the kernel uses for crash kernel.
>>
>
> Nacked-by: "Eric W. Biederman" <ebiederm@xmission.com>
>
> We can inspect the image we are going to load to get this information.
> In fact /sbin/kexec already inspects the image we are going to load
> to get this information. Putting this in the kernel adds kernel
> complexity for no gain.
>

/sbin/kexec is supported to know this, of course. But this is not for
/sbin/kexec, this is for user (or other programs) to observe the memory
information, so that he can know the memory he reserved is too much or not.

Without this, it is a little hard to use patch 2/2.