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RFC v1 - In-kernel NSD Prefetcher

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@nsdprojectdev nsdprojectdev released this 25 Jul 18:36

This release marks the RFC submission of NSD (Neural Storage Driver) to the Linux kernel mailing list.

What is NSD?

NSD is a learning page cache prefetcher that monitors I/O patterns via a hook in filemap_read() and prefetches pages using page_cache_sync_readahead(). It uses a synaptic Markov chain to learn access patterns at 4KB region granularity.

Branch

  • upstream-prep-v1 — Full kernel patch series ready for upstream

Patch Series

  1. mm/filemap: Add NSD prefetch hook point
  2. nsd: Core prediction engine
  3. Documentation: Add NSD filesystem documentation

Performance (x86_64, SATA SSD, kernel 7.0.0)

  • SQLite FTS (4GB table): -18.8% query time
  • Sequential 64K buffered: +22.6% throughput
  • Random 4K: +1.1% (noise)
  • Read latency: 130us (no regression)

Status

Sent as RFC to LKML and linux-mm on 2026-07-25. Awaiting architectural feedback.