Re: meminfo shows swap in use, but less than 100% of physical mem in use?

On 2006-09-13, Dave Hammond <dh1760@xxxxxxxxx> wrote:

Hi All,

I'm curious why /proc/meminfo (as well as 'top') would show a
significant amount of swap in use, when all of physical memory is not
in use? More to the point, I believe this is a case of having required
the swap at a certain point (we're debugging an application with a
serious memory leak), but the swap never having been released (or the
statistics never having been updated).

Some possibilities I can think of:

Other applications that are still running, that got swapped out to
allow your bog program to run, that have not had to swap those pages
in.

Do you use tmpfs? If so this goes into swap when needed.

Wasn't there talk of pre-emptive swapping out at some point for Linux?
So pages are written to disk ahead of time in case they need to be
swapped out quickly later. A similar thing would be keeping pages on
disk that have been swapped in but not changed so they can be swapped
out quickly later if needed.

- Richard

--
_/_/_/ _/_/_/ _/_/_/ Richard Corfield <Richard.Corfield@xxxxxxxxx>
_/ _/ _/ _/
_/_/ _/ _/ Time is a one way street, .
_/ _/ _/_/ _/_/_/ except in the Twighlight Zone 3^
.

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