Re: [PATCH] mm/mm_init.c: add debug messsge for dma zone

From: Haifeng Xu
Date: Thu Jun 08 2023 - 03:38:57 EST




On 2023/6/7 18:22, David Hildenbrand wrote:
> On 07.06.23 12:16, Michal Hocko wrote:
>> On Wed 07-06-23 09:07:34, Haifeng Xu wrote:
>>> If freesize is less than dma_reserve, print warning message to report
>>> this case.
>>
>> Why?
>
> I'd like to second that question, and add
>
> a) Did you run into that scenario?
> b) What can an admin do in that case with that error messages?

In theory,dma_reserve shouldn't exceed freesize, so the error messages can remind us
to verify whether the configuration of reserved memory is correct.

>
> If it reveals a buggy situation, maybe a WARN_ON_ONCE() is warranted ... but maybe only if anybody actually ran into that issue.
>