Re: [PATCH 0/8] Optional ZONE_DMA V1

Christoph Lameter
2006-09-12T17:33:50Z

On Tue, 12 Sep 2006, Jack Steiner wrote:

> I'm missing something here. On Altix, currently ALL of the memory is reported
> as being in the DMA zone:
>
> % cat /proc/budd*
> Node 0, zone DMA 3015 116 4 1 ...
> Node 1, zone DMA 4243 355 15 3 ...
> Node 2, zone DMA 4384 113 6 4 ...
>
> % cat /proc/zoneinfo
> Node 0, zone DMA
> pages free 5868
> ...
>
> The DMA slabs are empty, though.

This is wrong. All memory should be in ZONE_NORMAL since we have no DMA
restrictions on Altix.

> I assume your patch will switch Altix memory to a different zone, but what happens when
> drivers specify GFP_DMA.

GFP_DMA is ignored if there is no ZONE_DMA, same as GFP_DMA32 and
GFP_HIGHMEM.