RE: About the need of a swap area

[Alan Cox]

On Sun, 2002-07-28 at 00:01, Buddy Lumpkin wrote:
> Are you implying that it should be looking for pages to swap out this whole
> time to free up more space for filesystem and executable pages purely based
> on lru? Have you done testing to prove that this is a better approach than
> setting a threshold of when to wake up the lru mechanism?

Not all the time - when there is pressure to find more pages. 

> Solaris keeps dirty pages after they have been flushed to their backing
> store, it's just when the system has to choose something to flush that it
> preferences filesystem over anonymous and executable, what's wrong with
> that?

Many of its pages are both file system and executable. Solaris shares
read-only pages between the caches and the mappings into process spaces.
I can understand favouring flushing mapped files because swap is
generally slower than restoring a file backed mapping