>>>>> "Christoph" == Christoph Lameter <clameter@xxxxxxx> writes: Christoph> On Sat, 23 Sep 2006, Jes Sorensen wrote: >> If you want to take this path, are you then planning to move the < >> 4GB memory into ZONE_DMA32? We need a way to allocate memory within >> the 4GB zone for 32 bit DMA devices, especially on systems without >> an IOMMU. In fact, it's attractive to be able to get memory in the >> 4GB zone when possible even if a device supports DAC as it reduces >> the number of bus transactions since it can be done with a single >> address cycle instead of a dual. Christoph> IA64 has no ZONE_DMA32. ZONE_DMA has a 4GB boundary for Christoph> some architectures on IA64. The new page allocator call Christoph> alloc_pages_range() would be able to allocate pages below Christoph> the 4GB without having a ZONE_DMA (if necessary for 32 bit Christoph> devices without proper IOMMU support). I know the current code might not do whats really the right thing, but I wanted to make sure we didn't prevent it in the future. If alloc_pages_range() can do the job then that should be fine. Cheers, Jes - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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