Re: [PATCH] [scsi] Remove __GFP_DMA

From: Robert Hancock
Date: Thu May 24 2007 - 01:29:08 EST


Alan Cox wrote:
On Wed, 23 May 2007 15:17:08 -0400
"Salyzyn, Mark" <mark_salyzyn@xxxxxxxxxxx> wrote:

The 31 bit limit for some of these cards is a problem, we currently only
do __GFP_DMA for bounce buffer sg elements allocated for user supplied
references in ioctls.

I figure we should be using pci_alloc_consistent calls for these
allocations to more accurately acquire memory within the 31 bit limit if
necessary, we could switch to these to remove the need for the __GFP_DMA
flag in the aacraid driver?

That didn't used to work right on the AMD boards when I tried it last as
we ended up with a buffer that was mapped by the IOMMU for some reason
and that was not below 2GB.

The physical address you mean? If that is still happening then it needs to get fixed. The allocation should not succeed if it can't provide memory that's inside the DMA mask for the device..

--
Robert Hancock Saskatoon, SK, Canada
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Home Page: http://www.roberthancock.com/

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