# Re: \[PATCH 2/2\] fadump: Disable deferred page struct initialisation

- From: Michael Ellerman \<mpe@ellerman.id.au\>
- Date: 2016-08-03 11:34:25 
- List: linuxppc-dev
- Page: https://ratatoskr.run/linuxppc-dev/2016/08/6481605
- Thread: https://ratatoskr.run/linux-mm/2016/08/6481589/t.md

```text
Vlastimil Babka [ref] writes:

> On 08/03/2016 07:20 AM, Balbir Singh wrote:
>> On Tue, 2016-08-02 at 18:49 +0530, Srikar Dronamraju wrote:
>>> Fadump kernel reserves significant number of memory blocks. On a multi-node
>>> machine, with CONFIG_DEFFERRED_STRUCT_PAGE support, fadump kernel fails to
>>> boot. Fix this by disabling deferred page struct initialisation.
>>>
>>
>> How much memory does a fadump kernel need? Can we bump up the limits depending
>> on the config. I presume when you say fadump kernel you mean kernel with
>> FADUMP in the config?
>>
>> BTW, I would much rather prefer a config based solution that does not select
>> DEFERRED_INIT if FADUMP is enabled.
>
> IIRC the kdump/fadump kernel is typically the same vmlinux as the main 
> kernel, just with special initrd and boot params. So if you want 
> deferred init for the main kernel, this would be impractical.

Yes. Distros won't build a separate kernel, so it has to work at runtime.

cheers
```