Re: Strange behaviour of swap under 2.4.5-ac15

German Gomez Garcia
2001-06-18T13:17:57Z

On Mon, 18 Jun 2001, Andrea Arcangeli wrote:

> On Mon, Jun 18, 2001 at 12:14:01PM +0200, German Gomez Garcia wrote:
> > Hello,
> >
> > I've running 2.4.5-ac15 for almost a day (22 hours) and I found
> > some strange behaviour of the kswap, at least it was not present in
> > 2.4.5-ac9. The swap memory increase with time as the cache dedicated
> > memory also increase, that is swapping process at a very fast rate, even
> > when no program is getting more memory. Is that the expected behaviour?
> > An example, with no process running (just the usual daemons and
> > none of them getting extra memory) the command:
> >
> > free ; sleep 60; free
> >
> > total used free shared buffers cached
> > Mem: 513416 393184 120232 364 63276 254576
> > -/+ buffers/cache: 75332 438084
> > Swap: 530104 14228 515876
> >
> > total used free shared buffers cached
> > Mem: 513416 393192 120224 364 63276 258412
> > -/+ buffers/cache: 71504 441912
> > Swap: 530104 18064 512040
> >
> > Any idea?
>
> either apply this patch to 2.4.5ac15:
>
> ftp://ftp.us.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.5aa3/00_fix-unusable-vm-on-alpha-1
>
> (note it is not an alpha specific bug, it's just that I was triggering
> all the time on alpha so I called the patch that way)

It doesn't fix it, swapped memory and cache memory increase at a
rate of about 40K/s, swapping process very fast, even the "agetty"
processes get 64 out of 68 K swapped one or two minutes after booting.
This rate gets lower as nothing but the essential (4K of "agetty", etc) is
left in the physical memory.

> or better use 2.4.6pre3aa1:
>
> ftp://ftp.us.kernel.org/pub/linux/kernel/people/andrea/kernels/v2.4/2.4.6pre3aa1.bz2

I'll test this later as I cannot reboot the machine right now.
Just one question, is this kernel 'stable', I was running 2.4.5-ac9 for
a week without problems, even when 'stress-testing' the emu10k1 and the
mga modules.

Regards,

- german

PS: swapoff -a fixes the problem :-)
-------------------------------------------------------------------------
German Gomez Garcia | "This isn't right. This isn't even wrong."
<german@piraos.com> | -- Wolfgang Pauli