Re: Memory upgrade

On Tue, Oct 15, 2024 at 02:35:03PM +0200, Christian Schulte wrote:
> On 10/15/24 12:45, Claudio Jeker wrote:
> > On Tue, Oct 15, 2024 at 12:28:20PM +0200, Christian Schulte wrote:
> >> On 10/15/24 12:09, Stuart Henderson wrote:
> >>> On 2024-10-15, Zé Loff <zeloff@zeloff.org> wrote:
> >>>> On Tue, Oct 15, 2024 at 10:14:42AM +0200, Christian Schulte wrote:
> >>>>> ulimit -d `ulimit -aH | grep data | awk '{print $2}'`
> >>>>> ulimit -n `ulimit -aH | grep nofiles | awk '{print $2}'`
> >>>
> >>> ulimit -d `ulimit -dH` etc... but then there's no point setting a
> >>> separate hard limit in login.conf.
> >>
> >> Of course. I am the only user on that system and the only limits I want
> >> "my" xsession to be in effect on that system are the hard limits setup
> >> by the kernel. Those make the system swap for no apparent reasons. So.
> >> Why is this thing swapping?
> >
> > Because you are out of memory (most probably the usual amd64 problem of
> > running out of dma reachable memory and the pagedaemon going berserk about
> > that). You have plenty of ram just in the wrong spot.
> >
>
> According to the readings of top(1) or vmstat(8) I am not hitting any
> physical RAM limits. Still. The system starts swapping and I am yet to
> find out why it does. Maybe it just cannot fulfill requests for larger
> chunks of memory but does not "tell" an application about it and just
> commits itself to swapping? Makes no sense to me reading output of
> top(1) or vmstat(8) displaying that the system has swapped out more than
> half a GB to disk when nearly half of the RAM available to the system
> (8GB) is not even wired up. The system reports nearly 4GB of physical
> RAM available for allocation together with more than half of a GB
> swapped out to disk. Makes no sense.
>

Please read again. You are out of memory below 4GB (dma reachable physical
memory). The pagedaemon does a very poor job in that case and this is what
you see. It is a known issue and a fix will eventually emerge.

If the problem was trivial it would have been fixed already.
--
:wq Claudio