Title: SPIN: Seamless Operating System Integration of Peer-to-Peer DMA Between SSDs and GPUs


Abstract:

Recent GPUs enable Peer-to-Peer Direct Memory Access (P2P) from fast peripheral
devices like NVMe SSDs to exclude the CPU from the data path between them for
efficiency. Unfortunately, using P2P to access files is challenging because of
the subtleties of low-level nonstandard interfaces, which bypass the OS file I/O
layers and may hurt system performance.

SPIN integrates P2P into the standard OS file I/O stack, dynamically activating
P2P where appropriate, transparently to the user. It combines P2P with page cache
accesses, re-enables read-ahead for sequential reads, all while maintaining standard
POSIX FS consistency, portability across GPUs and SSDs, and compatibility with
virtual block devices such as software RAID.

We evaluate SPIN on NVIDIA and AMD GPUs using standard file I/O benchmarks, application
traces and end-to-end experiments. SPIN achieves significant performance speedups
across a wide range of workloads, exceeding P2P throughput by up to an order of magnitude.
It also boosts the performance of an aerial imagery rendering application by 2:6×
by dynamically adapting to its input-dependent file access pattern, and enables 3:3× higher
throughput for a GPU-accelerated log server.