On Tue, 12 Sep 2006, Andi Kleen wrote: > > There are no drivers depending on CONFIG_ZONE_DMA32. If CONFIG_ZONE_DMA32 > > is not set then the system assumes that DMA devices are capable of > > doing DMA to all of memory (which is mostly the case since most > > x86_64 motherboards only allow a max of 4GB of memory and advanced > > systems have DMA subsystems that handle I/O properly). > > Pretty much all have this problem (or do you know of a system with no > USB controller?) Most motherboards do not support more than 4GB ram. > I think I would prefer to not make GFP_DMA32 optional. > Adding a 4GB limit CONFIG to a 64bit kernel just seems somewhat > dumb. So is delivering motherboards for 64 bit with 4GB Ram. > Also what happens when someone still sets GFP_DMA? > iirc the SCSI stack tended to do that for some structures. > Will it fail? No it will be ignored. > Making GFP_DMA optional would be an interesting > experiment (I think it will break the floppies but other than that > a modern system might be fine). But it would be better Right some drivers are not available anymore that includes the floppy driver. > to warn the user stronger against it (most likely it will still > break a lot of older addin cards) and tell them about > the floppy. I still have some dusty set of floppies in my attic. Tried to use floppy a year to boot but it was such a hassle that I fell back to a usb stick. You can still have your floppies. Just do not disable support for ZONE_DMA. Its enabled by default. - 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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