Sudden grow of memory in "Laundry" state

[Mark Millard]

On 2018-Nov-5, at 16:53, RW via freebsd-hackers <freebsd-hackers at freebsd.org> wrote:

> On Mon, 5 Nov 2018 15:04:38 -0800
> Mark Millard via freebsd-hackers wrote:
> 
>> On 2018-Nov-5, at 14:21, Rozhuk Ivan <rozhuk.im at gmail.com> wrote:
>> 
>>> run, it was killed 
>>> Nov  5 21:05:09 firewall kernel: pid 96603 (testvm), uid 0, was
>>> killed: out of swap space Nov  5 21:05:15 firewall kernel: Nov  5
>>> 21:05:09 firewall kernel: pid 96603 (testvm), uid 0, was killed:
>>> out of swap space  
>> 
>> Unfortunately, the wording of this message is a misnomer for what
>> drives the kills: it is actually driven by being unable to gain more
>> free memory but FreeBSD will not swap-out processes that stay runnable
>> (or are running), only ones that are waiting.
> 
> When you say it wont swap-out processes, do you mean that literally, or
> do you mean it wont page-out from runable processes? Swapping processes
> shouldn't be an essential part of recovering memory, Linux doesn't even
> support it.

Paging is a different issue as I understand. Without paging,
no process could have a memory area bigger than RAM.

But, going in a different direction . . .

Turns out the example program in bugzilla 195882 is interesting
independent of any worries about kills or swap space use:

I ran an a.out built from the source but with 16 instead of 4
as the size controlling constant, in order use 16 GiByte for
an 8 GiByte aarch64 system.

Before the a.out run (after a fresh boot, form top):

Mem: 13M Active, 1240K Inact, 108M Wired, 28M Buf, 7757M Free
Swap: 28G Total, 28G Free

After the a.out had finished, from a separate top
run:

Mem: 2197M Active, 4937M Inact, 255M Wired, 186M Buf, 629M Free
Swap: 28G Total, 11M Used, 28G Free

No actual process (or group of them) was running using a large
amount of RAM at that point. Active and Inact are rather large.

With the system left idle, 15 minutes later or more, the
Active and Inact had not changed significantly, nor had Free.
The figures do seem odd.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)