Messages in this thread | | | From | David Mosberger <> | Date | Thu, 13 Jun 2002 08:09:32 -0700 | Subject | Re: [patch] pageattr update |
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Hi Ben,
I'm have a concern about the current change_page_attr() patch. It gives the impression that the GART memory always gets mapped write-combined. This is not always true. For example, on IA-64, attribute-aliasing issues are prevented by requiring IA-64 platforms to use coherent AGP DMA. In other words, the AGP memory will be mapped writeback, as usual.
As long as change_page_attr() is used for AGP-related stuff only, there is probably no real issue with the patch in its current form (its simply a no-op on most non-x86 platforms). However, I'm a bit worried that someone might start to use it for other things, such that change_page_attr() could no longer be a no-op on those platforms. Since the DMA coherency issue is an AGP specific issue, perhaps just renaming the macro to agp_change_page_attr() would take care of my concern. What do you think?
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