Messages in this thread | | | From | Logan Gunthorpe <> | Date | Thu, 1 Mar 2018 16:19:59 -0700 | Subject | Re: [PATCH v2 00/10] Copy Offload in NVMe Fabrics with P2P PCI Memory |
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On 01/03/18 04:00 PM, Benjamin Herrenschmidt wrote: > We use only 52 in practice but yes. > >> That's 64PB. If you use need >> a sparse vmemmap for the entire space it will take 16TB which leaves you >> with 63.98PB of address space left. (Similar calculations for other >> numbers of address bits.) > > We only have 52 bits of virtual space for the kernel with the radix > MMU.
Ok, assuming you only have 52 bits of physical address space: the sparse vmemmap takes 1TB and you're left with 3.9PB of address space for other things. So, again, why doesn't that work? Is my math wrong?
Logan
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