Steffen Persvold wrote:
>
> Another thing, when allocating memory with vmalloc, how can I be sure that the pages I get is
> adressable within 4GB (i.e I wan't to call pci_map_sg on this buffer for my 32bit PCI device without
> having to use bounce buffers ) ? On systems with less that 4GB of physical memory there's no
> problem, but what happens if you have more (lets say an IA64 server with 16GB of RAM) and don't have
> an IOMMU (like alpha and sparc) ?
>
> I noticed a vmalloc_32 in linux/vmalloc.h (the comment says "32bit PA addressable pages - eg for PCI
> 32bit devices"), but is that one platform independent (I see that it is only using GFP_KERNEL, while
> vmalloc is using GFP_KERNEL | __GFP_HIGHMEM) ? This issue goes for __get_free_pages too I guess.
>
Hmm, it helps looking back at old threads (which I actually was involved in).
What ever happened to Jens Axboe's "zone_dma32" patch ? Why wasn't it included in the main 2.4.6
kernel tree (seemed like a good idea to me) ?
Regards,
-- Steffen Persvold | Scalable Linux Systems | Try out the world's best mailto:sp@scali.no | http://www.scali.com | performing MPI implementation: Tel: (+47) 2262 8950 | Olaf Helsets vei 6 | - ScaMPI 1.12.2 - Fax: (+47) 2262 8951 | N0621 Oslo, NORWAY | >300MBytes/s and <4uS latency - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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