On 11/27/08, Andrea Arcangeli <address@hidden> wrote:
Hello everyone,
Once we finish fixing storage performance with a real
bdrv_aio_readv/writev (now a blocker issue), a pci_dma_single can be
added for zero copy networking (one NIC per VM, or VMDq, IOV
etc..). The DMA API should allow for that too.
The previous similar attempt by Anthony for generic DMA using vectored
IO was abandoned because the malloc/free overhead was more than the
performance gain. Have you made any performance measurements? How does
this version compare to the previous ones?
I think the pci_ prefix can be removed, there is little PCI specific.
For Sparc32 IOMMU (and probably other IOMMUS), it should be possible
to register a function used in place of cpu_physical_memory_rw,
c_p_m_can_dma etc. The goal is that it should be possible to stack the
DMA resolvers (think of devices behind a number of buses).