Little Alice joins the (page-cached) Caucus race

• Little Alice is fresh and wet - she needs to dry before going on.
• In page-cache-speak, Little Alice is too new to be sent to disk - perhaps
• some of her friends will join soon.
  • (these friends could be new writes that will over-write Little Alice,
  • or new writes adjacent to Little Alice,
  • or new reads that will want to query Little Alice's opinions).
• pdflush is a kernel thread that decides when to push Little Alice down to the block device.
• Memory pressure could also cause that to happen - if we're low on RAM, every cached item is a candidate for a flush.
• for info on pdflush-related tuneables: G. Smiths's "The Linux Page Cache and pdflush"

Originally written by guy keren