3 ms·

Free memory is always used by disk cache.

• effie 8y ago
  On Linux, not all of it, in my experience. If you have a lot of memory, some of it may be completely free.
  • bradknowles 8y ago
    Only a very small percentage is kept "free". Everything else should be made available to buffer cache or the application, etc....
  • deathanatos 8y ago
    It should gradually trend towards using the vast majority of the free space. The disk cache won't consume memory unless you're reading new, not-already-cached pages from disk; so if you're not reading enough data from disk, then it might not consume everything. (E.g., if you've rebooted recently, and just haven't read enough from disk to consume everything.) If you work w/ removable media, IME the cache will free the pages associated w/ that media when it's removed (as the cache must be assumed invalid when/if the media is plugged back in). Playing a DVD, and then ejecting it, would often result in a large drop in disk cache. (Back before Netflix…)