ideas for a swapping daemon

[Benjamin LaHaise <bcrl@kvack.org>]

Date: Thu, 18 Dec 1997 15:28:07 +0100 (MET)
From: Rik van Riel <H.H.vanRiel@fys.ruu.nl>
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To: linux-mm <linux-mm@kvack.org>
cc: linux-kernel <linux-kernel@vger.rutgers.edu>
Subject: ideas for a swapping daemon
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THIS FIRST MESSAGE WILL BE ON LINUX-KERNEL, I hope you'll all
F-up to linux-mm ONLY!!!
---------
Hi,

here it is, the thread about the swapping daemon <g>

I have the following ideas about the swapping daemon:

- it should swap out some processes if the paging daemon
  (kswapd) doesn't manage to keep nr_free_pages above
  (min_free_pages + free_pages_low)/2 for some time (ie: 5 seconds)
- then it should choose a low-priority, or long-sleeping program
  and swap it out (using the kswapd swapping mechanism, but using
  a 'force' flag, which could be implemented as an argument to the
  routines).
- as long as buffer+cache memory take up more than 1/3 of memory,
  it should try swapping that memory as well
- after a program has been swapped out, it can be swapped in by:
  - being swapped out some time (in case of a low-prio process swap)
  - being woken up (in case of a sleeping program being swapped out)

This is a very rough outline of what the swapping process should
do, and more ideas are needed...

looking forward to your comments,

Rik.

PS: I'd like this thread to continue on linux-mm only. The
linux-kernel people who'd like to follow it too, can easily
subscribe to linux-mm@kvack.org (majordomo@kvack.org) since
linux-mm tends to a quiet list...
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