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? > > If it reveals a buggy situation, maybe a WARN_ON_ONCE() is warranted ... but maybe only if anybody actually ran into that issue. > I didn't run into that scenario, just from code review. I think the account for reserved pages is similar to memmap pages, if freesize is less than memmap pages, it print a warning message, so for dma_reserve, it can also does the same thing.
