Re: Where might memory be reported?

From: Dave Hayes <dave_at_jetcafe.org>
Date: Mon, 7 Jun 2021 11:53:34 -0700
On Sun, 6 Jun 2021 16:09:13 -0700
Dave Hayes <dave_at_jetcafe.org> wrote:
> Consider this output from a 12.2-STABLE box (r368820) on amd64:
> 
>  # sysctl vm.stats.vm | grep count
>  vm.stats.vm.v_cache_count: 0
>  vm.stats.vm.v_user_wire_count: 0
>  vm.stats.vm.v_laundry_count: 0
>  vm.stats.vm.v_inactive_count: 121191
>  vm.stats.vm.v_active_count: 20836
>  vm.stats.vm.v_wire_count: 754310
>  vm.stats.vm.v_free_count: 254711
>  vm.stats.vm.v_page_count: 3993253
> 
> It should be pretty clear that there are missing pages. Where might they be
> and how might I find out?

Replying to myself here to make the situation clearer. :)

So I've noticed on random machines with various different and uncommon services,
there's an issue where the reported in-use memory (that I know about, see above)
continues to drop until and unless the machine is rebooted. If I do not reboot,
the machine will continue up until it runs out of swap space, at which point a
reboot is apparently mandatory. 

Naturally I am trying to monitor the situation, but I can't seem to find what
is using the extra memory.

I would like to file a bug about this, but first I would like to ensure that I
am not missing something obvious (or even non-obvious). 

As a related addendum, I used to know some of how FreeBSD virtual memory
worked but it would appear from 11->12 that this has changed. Thus, 
I am completely open to be pointed to any documentation or reading about how the
virtual memory system has changed (other than source code) between 11 and 12. 

Thanks in advance for cogent replies. 
-- 
Dave Hayes - Consultant - LA CA, USA - dave_at_dream-tech.com
>>>> *The opinions expressed above are entirely my own* <<<<

A person is deficient in understanding until they perceive
that there is a whole cycle of evolution possible within
themselves: repeating endlessly, offering opportunities for
personal development.
Received on Mon Jun 07 2021 - 18:53:34 UTC

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