2001-02-20 23:14:45

by J.A. Magallon

[permalink] [raw]
Subject: swap still stuck

Hi, everyone.

I seem to have again a problem that was talked about on the list, but I thought
it was yet corrected with some VM constants balancing.

I run 2.4.1-ac19-SMP. System works fine, but after a couple kernel untars
and an open netscape, starts to swap. Read buffers are still there. Do the
untars, launch netscape and instead of trashing buffers takes a bite on
swap.

Then you let netscape (what a mem hog example...) forgotten and start to do
some terminal work, config kernel, build, etc. Return to netscape and it is
much less responsible and disk starts to crawl to un-swap netscape. And
my 200 Mb of read buffers are still in main memory...

Is there any utility to say to kernel TROW AWAY YOUR READ BUFFERS ?. It looks
like it does not know how to do it.

I have finished some work session with just the last rxvt on screen, a mem like:

werewolf:~/soft/snd/alsa/alsa-utils# free
total used free shared buffers cached
Mem: 255524 244888 10636 0 94816 97052
-/+ buffers/cache: 53020 202504
Swap: 152576 9024 143552

but swap being 50Mb.

Why system does not try to drop read buffer pages before swapping ?


--
J.A. Magallon $> cd pub
mailto:[email protected] $> more beer

Linux werewolf 2.4.1-ac19 #1 SMP Mon Feb 19 21:52:31 CET 2001 i686


2001-02-21 23:14:14

by Rik van Riel

[permalink] [raw]
Subject: Re: swap still stuck

On Wed, 21 Feb 2001, J . A . Magallon wrote:

> I seem to have again a problem that was talked about on the
> list, but I thought it was yet corrected with some VM constants
> balancing.

> Why system does not try to drop read buffer pages before swapping ?

Actually, I've also started receiving complaints that the
system keeps processes in memory too much and evicts the
cache from memory too soon...

It all depends on what kind of workload you are using.

In the current 2.4 VM, I have not found a way to make this
balancing do the right thing automatically. If anybody has
an idea (or a patch) to make this thing work, let me know.

regards,

Rik
--
Virtual memory is like a game you can't win;
However, without VM there's truly nothing to lose...

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