Messages in this thread |  | | Date | Wed, 25 Nov 2009 16:56:32 +0900 | | Subject | Re: [PATCH] x86: fix gart iommu using for amd 64 bit system | | From | FUJITA Tomonori <> |
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On Wed, 25 Nov 2009 08:25:04 +0100 Ingo Molnar <mingo@elte.hu> wrote:
> > * FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> wrote: > > > On Tue, 24 Nov 2009 16:26:45 +0100 > > Ingo Molnar <mingo@elte.hu> wrote: > > > > > > > > * FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> wrote: > > > > > > > > don't think user will like to use SWIOTLB instead of swiotlb. > > > > > > > > I doubt that users care about a way to fix their problems. > > > > > > As far as swiotlb vs. GART goes, arguably a non-bouncing hw based > > > solution (GART) is superior to a bouncing one (swiotlb), right? > > > > Yeah, but GART is not a real IOMMU that always does address > > translation. If users want performance, they need 64bit DMA capable > > devices to skip GART. With such devices, GART and SWIOTLB are same. > > > > So this hacky GART workaround is useful for only people who use non > > 64bit DMA devices and broken BIOS with GART. IMO, it's not worth > > having the workaround. > > Well, what Yinghai is saying that for that (nonzero) subset of people > this change is a regression, and his patch fixes that. We dont do > regressions so this needs to be addressed.
OK, I guess that I have to wait until nobody cares about GART.
Anyway, my patch fixes his issue without any regression:
http://marc.info/?l=linux-kernel&m=125907069703595&w=2
I'll post the second version of it after you merge the following fix:
http://marc.info/?l=linux-kernel&m=125910650500523&w=2
Thanks,
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