{
  "slug": "bpfs",
  "term": "BPFS",
  "aliases": [
    "BPFS file system"
  ],
  "definition": "BPFS is a research file system that uses short-circuit shadow paging to commit persistent-memory updates below the file-system root.",
  "note": "The design combines aligned eight-byte failure-atomic writes, in-place appends and partial copy-on-write. Epoch barriers order persistence across epochs without forcing immediate durability. [bpfs-paper]",
  "status": "research",
  "advantages": [],
  "limitations": [
    {
      "text": "The proposed hardware contract is not implied by ordinary memory barriers or DAX support.",
      "citationIds": [
        "bpfs-paper"
      ]
    }
  ],
  "related": [
    "persistent-memory",
    "epoch-persistency",
    "persistence-ordering",
    "crash-consistency",
    "nova"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-11-13",
  "citations": [
    {
      "id": "bpfs-paper",
      "title": "Condit et al. Better I/O Through Byte-Addressable, Persistent Memory. SOSP 2009, sections 3.2, 4.3-4.4 and 5.",
      "url": "https://bantha.org/~jcondit/bpfs-sosp-2009.pdf",
      "accessed": "2026-11-13"
    },
    {
      "id": "hesela-pmem",
      "title": "Hesela: BPFS commit points and persistence barriers.",
      "url": "https://hesela.com/analyses/pmem-persistence-domains-dax/#bpfs",
      "accessed": "2026-11-13"
    }
  ],
  "provenance": [
    "Source synthesis of the SOSP 2009 research design. Evaluation used DRAM and PCM simulation, not current persistent-memory hardware. No prototype execution or benchmark replication."
  ]
}