Messages in this thread | | | Date | Mon, 10 Nov 2008 15:57:40 -0600 (CST) | From | Christoph Lameter <> | Subject | Re: [Q] Why does dma_alloc_coherent() of ia64 GFP_DMA? |
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On Mon, 10 Nov 2008, Robin Holt wrote:
> I am not sure what is be referred to here, but all of an Altix's memory is > DMA capable with the exception of the stuff covered by the MSPEC driver > (that is uncached memory). There are certainly all sort of special > requirements for doing transfers on Altix to eliminate memory ordering > problems, but nothing specific that I recall related to address ranges > and DMA.
But then ZONE_DMA has nothing to do with memory being dmaable or not. ZONE_DMA is for legacy devices that cannot do DMA to all of memory. I vaguely remember having stuffed all the memory into ZONE_NORMAL at some point. ZONE_DMA vanishes for Altix configurations.
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