Re: [PATCH v17 02/10] x86: kdump: make the lower bound of crash kernel reservation consistent

Leizhen (ThunderTown)
2021-12-15T02:10:34Z

On 2021/12/15 3:24, Catalin Marinas wrote:
> On Tue, Dec 14, 2021 at 08:07:58PM +0100, Borislav Petkov wrote:
>> On Fri, Dec 10, 2021 at 02:55:25PM +0800, Zhen Lei wrote:
>>> From: Chen Zhou <chenzhou10@huawei.com>
>>>
>>> The lower bounds of crash kernel reservation and crash kernel low
>>> reservation are different, use the consistent value CRASH_ALIGN.
>>
>> A big WHY is missing here to explain why the lower bound of the
>> allocation range needs to be 16M and why was 0 wrong?
>
> I asked the same here:
>
> https://lore.kernel.org/r/20210224143547.GB28965@arm.com
>
> IIRC Baoquan said that there is a 1MB reserved for x86 anyway in the
> lower part, so that's equivalent in practice to starting from
> CRASH_ALIGN.
>
> Anyway, I agree the commit log should describe this.

OK, I will add the description.