Re: [PATCH 3/6] Optional ZONE_DMA in the VM

Nick Piggin
2006-09-12T00:35:19Z

Christoph Lameter wrote:
> Make ZONE_DMA optional in core code.
>
> - ifdef definitions for ZONE_DMA and related code following
> the example for ZONE_DMA32 and ZONE_HIGHMEM.
>
> - Without ZONE_DMA, ZONE_HIGHMEM and ZONE_DMA32 we get to a
> ZONES_SHIFT of 0.
>
> - Modify the VM statistics to work correctly without a DMA
> zone.
>
> - Modify slab to not create DMA slabs if there is no
> ZONE_DMA.
>
> Signed-off-by: Christoph Lameter <clameter@sgi.com>

Nice. Looks like it should remove a bit of overhead.

I can't see from your patches, but what happens if someone asks
for a GFP_DMA page or dma slab allocation when there is no ZONE_DMA?

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SUSE Labs, Novell Inc.
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