Re: Swapping out old pages

[Rik van Riel <riel@nl.linux.org>]

On Tue, 18 May 1999, Karl Vogel wrote:

> - why does the swap out algorithm select the task with the largest
> RSS to free pages. If I'm not mistaken, the age of a page isn't
> considered?! Why is that? Am I overlooking something?

You're overlooking the fact that p->swap_cnt is only
recalculated when all processes have been scanned.

A new sweep starts at the process with the largest
swap_cnt -- but all processes are scanned eventually.

> - wouldn't it be beneficial if there is a parameter that allows
> you to specify that after a certain age, a page is swapped out to
> make room for the buffer cache.

The system already does that, and has been doing so
rather agressively since 2.1.89...

cheers,

Rik -- Open Source: you deserve to be in control of your data.
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