In mount_load_proc_self_mountinfo(), device_found_node() is synchronously called
during the traversal of mountinfo entries. When there are a large number of
mount points, and the device types are not significantly different, this results
in excessive time consumption during device discovery, causing a performance
bottleneck. This issue is particularly prominent on servers with a large number
of cores in IDC.
This patch decouples device discovery from the mountinfo traversal process,
avoiding redundant device operations. As a result, it significantly improves
performance, especially in environments with numerous mount points.
Signed-off-by: Chen Guanqiao <chen.chenchacha@foxmail.com>
Follow-up for fa693fdc7e.
The documentation says the option takes a boolean or one of the "self"
and "identity". But the parser uses private_users_from_string() which
also accepts "off". Let's drop the implicit support of "off".
Otherwise, the log is shown even when getting properties.
Even though it is in the debug level, that's quite noisy.
[ 338.785847] TEST-55-OOMD.sh[1624]: Oct 07 16:35:15 H systemd[1]: TEST-55-OOMD-testmunch.service: Unit not running in private mount namespace, cannot live mount
[ 338.786985] TEST-55-OOMD.sh[1624]: Oct 07 16:35:17 H systemd[1]: TEST-55-OOMD-testmunch.service: Unit not running in private mount namespace, cannot live mount
[ 338.787412] TEST-55-OOMD.sh[1624]: Oct 07 16:35:20 H systemd[1]: TEST-55-OOMD-testmunch.service: Unit not running in private mount namespace, cannot live mount
[ 338.791776] TEST-55-OOMD.sh[1624]: Oct 07 16:35:22 H systemd[1]: TEST-55-OOMD-testmunch.service: Unit not running in private mount namespace, cannot live mount
[ 338.792938] TEST-55-OOMD.sh[1624]: Oct 07 16:35:24 H systemd[1]: TEST-55-OOMD-testmunch.service: Unit not running in private mount namespace, cannot live mount
[ 338.793225] TEST-55-OOMD.sh[1624]: Oct 07 16:35:26 H systemd[1]: TEST-55-OOMD-testmunch.service: Unit not running in private mount namespace, cannot live mount
[ 338.793424] TEST-55-OOMD.sh[1624]: Oct 07 16:35:28 H systemd[1]: TEST-55-OOMD-testmunch.service: Unit not running in private mount namespace, cannot live mount
[ 338.796448] TEST-55-OOMD.sh[1624]: Oct 07 16:35:31 H systemd[1]: TEST-55-OOMD-testmunch.service: Unit not running in private mount namespace, cannot live mount
[ 338.797997] TEST-55-OOMD.sh[1624]: Oct 07 16:35:33 H systemd[1]: TEST-55-OOMD-testmunch.service: Unit not running in private mount namespace, cannot live mount
[ 338.799206] TEST-55-OOMD.sh[1624]: Oct 07 16:35:35 H systemd[1]: TEST-55-OOMD-testmunch.service: Unit not running in private mount namespace, cannot live mount
The method was added with migration of resources in mind (e.g. process's
allocated memory will follow it to the new scope), however, such a
resource migration is not in cgroup semantics. The method may thus have
the intended users and others could be guided to StartTransientUnit().
Since this API was advertised in a regular release, start the removal
with a deprecation message to callers.
Eventually, the goal is to remove the method to clean up DBus API and
simplify code (removal of cgroup_context_copy()).
Part of DBus docs is retained to satisfy build checks.
Catch up with the nice little toys the kernel fs developers have added
for us. Preferably, let's make use of the new F_DUPFD_QUERY fcntl() call
that checks whether two fds are just duplicates of each other
(duplicates as in dup(), not as in open() of the same inode, i.e.
whether they share a single file offset and so on).
This API is much nicer, since it is a core kernel feature, unlike the
kcmp() call we so far used, which is part of the (optional)
checkpoint/restore stuff.
F_DUPFD_QUERY is available since kernel 6.10.
On Ubuntu/Debian infrastructure QEMU crashes a lot, so mark the test
as skipped in that case as there's nothing we can do about it and
we shouldn't mark runs as failed
This adds the ExtraFileDescriptor property to StartTransient dbus API
with format "a(hs)" - array of (file descriptor, name) pairs. The FD
will be passed to the unit via sd_notify like Socket and OpenFile.
systemctl show also shows ExtraFileDescriptorName for these transient
units. We only show the name passed to dbus as the FD numbers will
change once passed over the unix socket and are duplicated, so its
confusing to display the numbers.
We do not add this functionality for systemd-run or general systemd
service units as it is not useful for general systemd services.
Arguably, it could be useful for systemd-run in bash scripts but we
prefer to be cautious and not expose the API yet.
Fixes: #34396
Chen Guanqiao
Yu Watanabe
Luca Boccassi
Michal Koutný
David Joaquín Shourabi Porcel
Lennart Poettering
Luca Boccassi
Ryan Wilson
Daan De Meyer
Ivan Kruglov
Thomas Blume