Linux pagecache doesn't use hugepages, but definitely when doing direct I/O into application buffers, would make sense to use hugepages for that. I plan to run tests on various database engines next - and many of them support using hugepages (for shared memory areas at least).

Thanks! Apparently, they did add it for tmpfs, and discussed it for ext4. https://lwn.net/Articles/718102/

Good point - something to test, once I get to the filesystem benchmarks!

In the networking world (DPDK) huge pages and static pinning everything is a huge deal as you have very few cpu cycles per network packet.

Yep - and there's SPDK for direct NVMe storage access without going through the Linux block layer: https://spdk.io

(it's in my TODO list too)