From what I understand, there are hardware-implemented techniques to keep the CPU L1 cache coherent with the data in RAM (when performing read/writes on a shared variable)

  • every write will invalidate the corresponding entry in all CPU caches
  • or, every write will update the corresponding entry on all other CPU caches

Is there a similar mechanism (software/hardware-wise) for maintaining consistency on the page cache? As far as I understand, the page cache is a write-back cache, meaning writes only show up in the cache, but only show up on disk later "asynchronously" (e.g. when the page gets evicted from the cache).

1 Answer 1


system calls sync or fsync instruct disk driver to make the writes persisted but it does not guarantee. Also both the calls are blocking or synchronous.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .