Messages in this thread | | | Date | Tue, 12 Feb 2008 16:57:19 -0800 (PST) | From | Christoph Lameter <> | Subject | RE: [ofa-general] Re: Demand paging for memory regions |
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On Tue, 12 Feb 2008, Felix Marti wrote:
> > I don't know anything about the T3 internals, but it's not clear that > > you could do this without a new chip design in general. Lot's of RDMA > > devices were designed expecting that when a packet arrives, the HW can > > look up the bus address for a given memory region/offset and place the > > packet immediately. It seems like a major change to be able to > > generate a "page fault" interrupt when a page isn't present, or even > > just wait to scatter some data until the host finishes updating page > > tables when the HW needs the translation. > > That is correct, not a change we can make for T3. We could, in theory, > deal with changing mappings though. The change would need to be > synchronized though: the VM would need to tell us which mapping were > about to change and the driver would then need to disable DMA to/from > it, do the change and resume DMA.
Right. That is the intend of the patchset.
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