[termie]

This is promising, but for dedicated high-performance I/O I am much more interested in how the SPDK is progressing. Avoiding syscalls is great, but without any benchmarks I wonder about the benefits over mmap and vectorizing. You still have to contend with locking, interrupts, copying, and ring 0 abstraction impedence.

[1] https://spdk.io

[jandrewrogers]

SPDK follows the same pattern as DPDK (for networking) but it has much less of a practical use case in my experience. You can easily outperform mmap() etc using io_submit() interface that already exists, saturating the capabilities of fast storage hardware, and the overhead of io_submit() is nominal if you are using it well. SPDK won't meaningfully increase your I/O throughput and the API is significantly more difficult to use. I've played around with SPDK in database storage engines and I find it to be inferior for the purpose compared to io_submit() in practical implementations. The number of IOPS required to make SPDK worth considering would be indicative of a more fundamental design flaw in your storage architecture, at least for the foreseeable future.

DPDK, by contrast, can dramatically improve networking throughput and performance. While also not the most friendly API to use, it undeniably improves CPU efficiency for packet processing and without an obviously better alternative.

[devwastaken]

Do you have a high performing io_submit() example?