[n00b101]

Will combining SPDK with the usermode driver for the Intel I/OAT DMA engine provide the necessary building blocks for a complete solution (network+storage)?

And can this be combined with PCIe-attached accelerators (e.g. Xeon Phi or GPUs)?

[drv]

The SPDK libraries are mostly storage-specific components (the I/OAT DMA engine can be used for generic copy offload, but it is particularly useful for copying between network and storage buffers). SPDK itself does not provide any network functionality.

I am not familiar enough with the Xeon Phi or GPU programming model to say for sure, but they could possibly be used to offload tasks like hashing/dedup or other storage-related functions.

[n00b101]

> they could possibly be used to offload tasks like hashing/dedup or other storage-related functions

Sorry, I was not referring to accelerating storage-related functions, I was wondering about efficient DMA copy from one PCIe device (Intel NVM storage) to another (Xeon Phi accelerator) which would be for useful many different functions, if the NVM storage device capacity is much larger than the accelerator device memory.

[drv]

Ah, I see. The I/OAT DMA copy offload is essentially equivalent to an asynchronous memcpy(), so anything addressable on the memory bus could be a source or destination (with some caveats about alignment requirements and pinned pages if copying to/from RAM).