{
  "slug": "informed-prefetching",
  "term": "Informed prefetching",
  "aliases": [
    "Transparent Informed Prefetching",
    "TIP"
  ],
  "definition": "Informed prefetching uses application disclosures of future file accesses to schedule advance reads under shared resource constraints.",
  "note": "Disclosure identifies future accesses in file-level terms rather than prescribing a lower-level policy. The historical TIP prototype could exploit nonsequential and cross-file access knowledge. [tip94]\n\nTIP-2 balances buffers for advance reads, hinted reuse and unhinted LRU caching using estimated execution-time costs and benefits. The three demands compete for memory. [tip95]",
  "advantages": [],
  "limitations": [
    {
      "text": "Application hints describe expected accesses, not completed reads or guaranteed cache residency.",
      "citationIds": [
        "tip94"
      ]
    }
  ],
  "related": [
    "tiptoe",
    "readahead",
    "table-based-prefetching",
    "prefetch-wastage"
  ],
  "status": "research",
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-11-14",
  "citations": [
    {
      "id": "tip94",
      "title": "Patterson and Gibson. Exposing I/O Concurrency with Informed Prefetching. PDIS 1994, sections 1-2.",
      "url": "https://www.pdl.cmu.edu/Publications/HTML-Papers/PDIS94/final.fm.shtml",
      "accessed": "2026-11-14"
    },
    {
      "id": "tip95",
      "title": "Patterson et al. Informed Prefetching and Caching. SOSP 1995, sections 3-4 and 6-7.",
      "url": "https://www.cs.cmu.edu/afs/cs/project/pdl/ftp/TIP/SOSP15.pdf",
      "accessed": "2026-11-14"
    }
  ],
  "provenance": [
    "Historical primary-source review; the Mach 3.0 TIP prototype and OSF/1 TIP-2 evaluation are distinct systems, not current Linux implementations."
  ]
}