Re: [PATCH 3/3] dma-pool: limit DMA and DMA32 zone size pools

[Christoph Hellwig]

On Mon, Aug 22, 2022 at 02:09:13PM +0200, Michal Hocko wrote:
> OK, so you are worried about configurations that lack ZONE_DMA32 because
> that memory range is covered by ZONE_DMA? I thought though simply do not
> have CONFIG_ZONE_DMA32. Or am I wrong here?

Zones can disappear when they are empty.  Normally that affects
ZONE_NORMAL and ZONE_HIGHMEM, but it can also happen to ZONE_DMA32
when there is not enough memory.