journalctl --unit= already did this, and allows you to tail all the logs
for a certain slice easily. It seemed only natural to make --user-unit
behave in a similar way.
The _SYSTEMD_USER_SLICE field was not documented as being added by
journald, so I have added that to the documentation too.
Furthermore, I have documented the existing behaviour of --unit= and the
new behaviour of --user-unit=
The behaviour was actually not documented before, so I am also OK with
removing the match for the --unit= command instead. The user would then
have to manually provide _SYSTEMD_SLICE= filter to journalctl in both
cases. Both options work for me.
If logging disappears issues are hard to debug, hence let's give
journald a slight edge over other services when the OOM killer hits.
Here are the special adjustments we now make:
systemd-coredump@.service.in OOMScoreAdjust=500
systemd-journald.service.in OOMScoreAdjust=-250
systemd-udevd.service.in OOMScoreAdjust=-1000
(i.e. the coredump processing is made more likely to be killed on OOM,
and udevd and journald are less likely to be killed)
The alternative would be to recreate the cache, but dropins can be created very
often for transient settings, so updating the cache seems like a much faster
option.
Fixes#13287.
The file descriptor was opened with O_CLOEXEC, so in practice this doesn't
change too much, but it seems cleaner to always close the old fd when
changing the device path.
Ubunut autopkgtest fails with:
405/501 test-journal-flush FAIL 0.74 s (killed by signal 6 SIGABRT)
--- command ---
SYSTEMD_KBD_MODEL_MAP='/tmp/autopkgtest.BgjJJv/build.yAM/systemd/src/locale/kbd-model-map' SYSTEMD_LANGUAGE_FALLBACK_MAP='/tmp/autopkgtest.BgjJJv/build.yAM/systemd/src/locale/language-fallback-map' PATH='/tmp/autopkgtest.BgjJJv/build.yAM/systemd/build-deb:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games' /tmp/autopkgtest.BgjJJv/build.yAM/systemd/build-deb/test-journal-flush
--- stderr ---
Assertion 'r >= 0' failed at src/journal/test-journal-flush.c:48, function main(). Aborting.
-------
It's hard to say what is going on here without any error messages whatsoever.
The test goes into deep details of journal file handling, so it needs to also
do logging on its own.
