Re: Ongoing 2.4 VM suckage

jlnance
2001-08-03T13:07:42Z

On Thu, Aug 02, 2001 at 07:27:42PM -0300, Rik van Riel wrote:
> On Thu, 2 Aug 2001, Jeffrey W. Baker wrote:
>
> > I'm telling you that's not what happens. When memory pressure
> > gets really high, the kernel takes all the CPU time and the box
> > is completely useless. Maybe the VM sorts itself out but after
> > five minutes of barely responding, I usually just power cycle
> > the damn thing. As I said, this isn't a classic thrash because
> > the swap disks only blip perhaps once every ten seconds!
>
> What kind of workload are you running ?
>
> We could be dealing with some weird artifact of
> virtual page scanning here, or with a strange
> side effect of recent VM changes ...

Rik,
FWIW, I am seeing this sort of thing too, though I am running a 2.4.5
kernel so I am a little out of date. Its a large machine with 2G of ram,
4G of swap, and 2 CPUs. You dont have to actually use all the memory either.
When my process gets to about 1.5G and starts doing lots of file I/O, the
machine can just disappear for several minutes. I will be sshed in and
I can not even get my shell to give me a new prompt when I hit return. It
will eventually sort it self out, but it might take 15 minutes. I will try
and get a more recent kernel installed, but the machine is not under my
control, so I dont get to decide when that happens.

Thanks,

Jim