Messages in this thread | | | Date | Tue, 30 Jun 2020 11:57:21 +0200 | From | Joerg Roedel <> | Subject | Re: [PATCH v2 0/2] iommu/amd: Don't use atomic64_t for domain->pt_root |
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On Fri, Jun 26, 2020 at 08:30:21AM -0400, Qian Cai wrote: > BTW, from the previous discussion, Linus mentioned, > > “ > The thing is, the 64-bit atomic reads/writes are very expensive on > 32-bit x86. If it was just a native pointer, it would be much cheaper > than an "atomic64_t". > “ > > However, here we have AMD_IOMMU depend on x86_64, so I am wondering if > it makes any sense to run this code on 32-bit x86 at all?
No, it doesn't, the driver is not supported on 32bit and probably never will. I skip this patch and only apply the first one, as it is an improvement in itself.
Regards,
Joerg
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