Re: Strange behaviour of swap under 2.4.5-ac15

Luigi Genoni
2001-06-18T13:35:20Z

On Mon, 18 Jun 2001, German Gomez Garcia wrote:

> 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.
>
I was having similar problems with a sun 3500 with 4 GB of RAM
running 2.4.5 (no problems of this kind with 2.4.4), and this
patch fixed my problems under eavy stress.

I was having the most of memory free and a lot of swap allocated,
and system swapping to dead.

Now it works, with other problems, but when i have time and
permission to try to debug them..... :).

Maybe there could be some HW related reason because of which it fixed for
my sun and not for you...

Luigi