[TUHS] Overgrown ffox (was: The Unix shell: a 50-year view)

[Kevin Bowling]

Try typing “about:memory” into the address bar and hit measure.  You will
see where it is all going.

On Wed, Jul 7, 2021 at 11:48 PM Tomasz Rola <rtomek at ceti.pl> wrote:

> On Wed, Jul 07, 2021 at 08:50:51PM +0000, Michael Kjörling wrote:
> > On 7 Jul 2021 20:32 +0200, from rtomek at ceti.pl (Tomasz Rola):
> > > An excerpt from my ps:
> > >
> > > USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME
> COMMAND
> > >
> > > xxxon    12331 12.5 20.4 5898360 2519640 ?     TNsl Mar29 18278:11
> firefox-esr
> >
> > I'm going to stick my neck out here by saying that the VSZ and RSS
> > values reported by ps, at least for Firefox, are largely meaningless.
> >
> > I started my usual Firefox instance, which has a handful of plugins,
> > about a metric gazillion bookmarks, and has been my main web browser
> > profile for years (so it probably has collected some crud over time).
> > `ps auxw` reported that process as having a total RSS of a whopping
> > 374 GB.
> >
> > It is downright _impossible_ that Firefox could actually be using that
>
> This is quite strange for me. Without looking at your system I can only
> suspect it has something to do with multithreading.
>
> If I do two different commands as root, with firefox pid here
> .eq. 12331, as above:
>
> =>  (500 15):    lsof -p 12331 | wc -l
> 402
>
> =>  (500 17):   lsof | awk '$2==12331' | wc -l
> 22055
>
> The first column gives a name, and in second case it not always is
> 'firefox'. I am yet to study manpage for lsof and play with it, but it
> surely shows interesting things.
>
> On my system, when firefox gets killed, 'free' shows a difference - if
> I recall, free mem increases by the size of rss plus all the stuff
> which was opened and released from buffers. I did not pay much
> attention, I assumed numbers would match and this is what they
> probably did :-).
>
> OS on my box used to report to me as Debian, and still does, but some
> years ago I have decided to skip the usual system upgrade, and after
> some more time I started to upgrade various elements by hand. So it is
> more like a tattered patchwork right now. But it does what I expect,
> hopefully.
>
> [...]
> > That's a _factor almost 2300x_ difference between the reported RSS,
> > and the amount of memory that was actually freed up by closing the
> > browser.
>
> Yeah, strange.
>
> [...]
> > On modern systems, with everything from shared libraries to
> > memory-mapped I/O to routine use of memory overcommitting, the
> > resident set size is clearly a poor indicator of the actual amount
> > of memory actively used by a complex process.
>
> Hard to tell - first I would like to learn where the hundred-giga rss
> came from...
>
> --
> Regards,
> Tomasz Rola
>
> --
> ** A C programmer asked whether computer had Buddha's nature.      **
> ** As the answer, master did "rm -rif" on the programmer's home    **
> ** directory. And then the C programmer became enlightened...      **
> **                                                                 **
> ** Tomasz Rola          mailto:tomasz_rola at bigfoot.com             **
>
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