Bug#921280: systemd-cgtop no longer shows memory usage

[Szabolcs Fruhwald]

On Thu, Feb 28, 2019 at 10:48 AM Michael Biebl <email at michaelbiebl.de> wrote:
>
> Control: tags -1 + moreinfo
>
> Hi
>
> On Wed, 20 Feb 2019 14:20:19 -0800 Szabolcs Fruhwald
> <sfruhwald at google.com> wrote:
> > We experienced the same issue. After debugging it with gdb, found the
> > culprit and created a fix / PR on systemd github repo:
> > https://github.com/systemd/systemd/pull/11775
>
>
> Hm, interesting.
> I see that this particular PR is not part of v241.
> That said, when I run systemd-cgtop I *do* see the memory usage column
> with 241-1
>
> Anthony, could you please re-test with this version and report back?
>
> Regards,
> Michael
>
> --
> Why is it that all of the instruments seeking intelligent life in the
> universe are pointed away from Earth?
>

Yes, this is not part of v241. However, this issue (no memory / io
columns shown) is happening only when the cpu_accounting_is_cheap()
returns true, which depends on kernel version (existence of a
particular patch) / used cgroup hierarchy (unified / legacy), see the
code here: https://github.com/systemd/systemd/blob/5bcffb4b549c0d115d8e40137ea885b7568ec6cb/src/basic/cgroup-util.c#L2935
So, for example, we only experienced this issue after moving onto
4.19, with 4.9 it was working well.