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As Andi pointed out: CONFIG_GENERIC_ISA_DMA only disables the ISA DMA channel management. Other functionality may still expect GFP_DMA to provide memory below 16M. So we need to make sure that CONFIG_ZONE_DMA is set independent of CONFIG_GENERIC_ISA_DMA. Undo the modifications to mm/Kconfig where we made ZONE_DMA dependent on GENERIC_ISA_DMA and set theses explicitly in each arches Kconfig. Reviews must occur for each arch in order to determine if ZONE_DMA can be switched off. It can only be switched off if we know that all devices supported by a platform are capable of performing DMA transfers to all of memory (Some arches already support this: uml, avr32, sh sh64, parisc and IA64/Altix). In order to switch ZONE_DMA off conditionally, one would have to establish a scheme by which one can assure that no drivers are enabled that are only capable of doing I/O to a part of memory, or one needs to provide an alternate means of performing an allocation from a specific range of memory (like provided by alloc_pages_range()) and insure that all drivers use that call. In that case the arches alloc_dma_coherent() may need to be modified to call alloc_pages_range() instead of relying on GFP_DMA. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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| arc | ||
| au1000 | ||
| basler/excite | ||
| boot | ||
| cobalt | ||
| configs | ||
| ddb5xxx | ||
| dec | ||
| emma2rh | ||
| gt64120 | ||
| jazz | ||
| jmr3927 | ||
| kernel | ||
| lasat | ||
| lib | ||
| lib-32 | ||
| lib-64 | ||
| math-emu | ||
| mips-boards | ||
| mm | ||
| momentum | ||
| oprofile | ||
| pci | ||
| philips/pnx8550 | ||
| pmc-sierra | ||
| qemu | ||
| sgi-ip22 | ||
| sgi-ip27 | ||
| sgi-ip32 | ||
| sibyte | ||
| sni | ||
| tx4927 | ||
| tx4938 | ||
| vr41xx | ||
| defconfig | ||
| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||