Introduce Slice.ActivatingConcurrencyMax to limit how many units
within a slice hierarchy may be in activating state concurrently.
Expose the setting over D-Bus, support transient/property parsing,
enforce it during unit start dispatch, and re-check queued starts when
units leave activating state.
Document the new slice option and add a PID1 concurrency test covering
queued startup behavior.
Currently only a single job for a single unit can be enqueued atomically,
so there is no guarantee that, e.g., starting a unit and its socket
at the same time will happen in the same transaction. That forces
callers to 'know' the right order in which to start new units being
installed, or failures will occur. It also means some ordering
constraints are ignored, in case the separate calls are done
in the wrong manual order.
Add a new EnqueueUnitJobMany() D-Bus method that takes a list of units
to start.
Fixes https://github.com/systemd/systemd/issues/8102
Co-authored-by: Michal Koutný <mkoutny@suse.com>
We already support exponential backoff for automatic restarts via
RestartSec=/RestartSteps=/RestartMaxDelaySec=, but there is no way to
randomize the restart delay. When many instances of a service fail at
the same time (e.g. because a shared resource briefly went away) they
are all restarted in lockstep, creating a thundering herd problem.
So this commit adds a simple `RestartRandomizedDelaySec=` service
option which is similar to the timer `RandomizedDelaySec=` and
adds a randomized restart delay.
Acquiring a LUO session from /dev/liveupdate requires privileges,
and also the device is a single-owner driver so only a single
process can open it at any given time.
Add a LUOSession= service settings that allows units running
without privileges to get a session assigned to them.
The kernel imposes a 64 chars limit on session names, which is
too short to avoid clashes, so derive a hash from joining the
unit name with the parameter name, that way two units using
the same setting don't clash.
Add support for configuring cpuset partition type via the
CPUSetPartition= unit file setting. This controls the kernel's
cpuset.cpus.partition cgroup attribute.
The setting takes one of "member", "root", or "isolated". This is
useful for real-time workloads that require dedicated CPU resources
without interference from other processes.
When set, systemd will write the partition type to the
cpuset.cpus.partition cgroup file. If the kernel rejects the value
(e.g., due to partition hierarchy rules), a warning is logged and the
unit continues with the kernel's default partition type.
Co-developed-by: Claude Sonnet 4.5 <noreply@anthropic.com>
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Introduce a counter that tracks how many configuration reloads have
been successfully completed by the manager. The increment lives in
manager_reload() right after the "point of no return", so failed
reload attempts that bail out earlier (e.g. during serialization)
do not bump the counter.
It is accessible as a new ReloadCount property to
org.freedesktop.systemd1.Manager (D-Bus) and ReloadCount to
io.systemd.Manager.Describe (Varlink).
Also add an integration test for ReloadCount
that verifies that the new ReloadCount property increments by one per
daemon-reload, accumulates correctly across multiple reloads, and that
D-Bus and Varlink return identical values. Also tests that the counter
reset after a reexec.
Co-developed-by: Claude Opus 4.7 <noreply@anthropic.com>
Signed-off-by: Simon Lucido <simonlucido@meta.com>
Useful for packaging scripts, when units are removed.
When multiple markers are assigned without +/-, the last one wins.
When using +/-, the job merging logic is followed to the extent possible.
Transparent Hugepages (THP) is a Linux kernel feature that manages
memory using larger pages (2MB on x86, compared to the default 4KB).
The main goal is to improve memory management efficiency and system
performance, especially for memory-intensive applications.
However, it can cause drawbacks in some scenarios, such as memory
regression and latency spikes. THP policy is governed for the entire
system via /sys/kernel/mm/transparent_hugepage/enabled.
However, it can be overridden for individual workloads via prctl(2)
call.
MemoryTHP= is used to disable THPs at exec-invoke to stop
providing THPs for workloads where the drawbacks outweigh the advantages.
When set to "disable", MemoryTHP= disables THPs completely for the
process, irrespecitive of global THP controls.
When set to "madvise", MemoryTHP= disables THPs for the process except
when specifically madvised by the process with MADV_HUGEPAGE or MADV_COLLAPSE.
Closes#3829
Alternative to #35417
I don't think the individual "WasOnDependencyCycle" attrs on units
are particularly helpful and comprehensible, as it's really about
the dep relationship between them. And as discussed, the dependency
cycle is not something persistent, rather local to the currently
loaded set of units and shall be reset with daemon-reload (see also
https://github.com/systemd/systemd/issues/35642#issuecomment-2591296586).
Hence, let's report system state as degraded and point users to
the involved transactions when ordering cycles are encountered instead.
Combined with log messages added in 6912eb315f
it should achieve the goal of making ordering cycles more observable,
while avoiding all sorts of subtle bookkeeping in the service manager.
The degraded state can be reset via the existing ResetFailed() manager-wide
method.
When Type=notify-reload got introduced, it wasn't intended to be
mutually exclusive with ExecReload=. However, currently ExecReload=
is immediately forked off after the service main process is signaled,
leaving states in between essentially undefined. Given so broken
it is I doubt any sane user is using this setup, hence I took a stab
to rework everything:
1. Extensions are refreshed (unchanged)
2. ExecReload= is forked off without signaling the process
3a. If RELOADING=1 is sent during the ExecReload= invocation,
we'd refrain from signaling the process again, instead
just transition to SERVICE_RELOAD_NOTIFY directly and
wait for READY=1
3b. If not, signal the process after ExecReload= finishes
(from now on the same as Type=notify-reload w/o ExecReload=)
4. To accomodate the use case of performing post-reload tasks,
ExecReloadPost= is introduced which executes after READY=1
The new model greatly simplifies things, as no control processes
will be around in SERVICE_RELOAD_SIGNAL and SERVICE_RELOAD_NOTIFY
states.
See also: https://github.com/systemd/systemd/issues/37515#issuecomment-2891229652
This allows a service to reuse the user namespace created for an
existing service, similarly to NetworkNamespacePath=. The configuration
is the initial user namespace (e.g. ID mapping) is preserved.
closes#37602, see there for extra motivation and considered
alternatives.
On typical systems, only few services need to create SUID/SGID files.
This often is limited to the user explicitly setting suid/sgid, the
`systemd-tmpfiles*` services, and the package manager. Allowing a
default to globally restrict creation of suid/sgid files makes it easier
to apply this restriction precisely.
## testing done
- built on aarch64-linux and x86_64-linux
- ran a VM test on x86_64-linux, checking for:
- VM system boots successfully
- defaults apply (both `yes`, `no`, and undefined)
- systemd tmpfiles can set suid/sgid on journal log path
- Other services explicitly defining `RestrictSUIDSGID=no` can create
suid files
Add a new option PrivateBPF= to mount a new instance of bpffs within a
namespace.
PrivateBPF= can be set to "no" to use the host bpffs in readonly mode
and "yes" to do a new mount.
The mount is done with the new fsopen()/fsmount() API because in future
we'll hook some commands between the two calls.
Alternative to b50f6dbe57
The commit naively returned early from socket_enter_running(), which however
is quite problematic, as the socket will be woken up over and over again
without doing a thing, until we eventually hit Poll/TriggerLimit*=.
On top of that it requires hacks to hold the start job for initrd-switch-root.service
up. Overall I doubt that is the right approach.
Let's instead hook this into our job engine, and try to activate
the service again when some other units are stopped. If all installed
jobs have been run yet we're still seeing the conflict or the manually
selected timeout is reached, fail the socket as before.
This controls the new SO_PASSRIGHTS socket option in kernel v6.16.
Note that I intentionally choose a different naming scheme than
Pass*=, since all other Pass*= options controls whether some extra
bits are attached to the message, while this one's about denying
file descriptor transfer and it feels more explicit this way.
And diverging from underlying socket option name is precedented
by Timestamping=. But happy to change it to just say PassRights=
if people disagree.
Our baseline is v5.4 and cgroup v2 is enforced now,
which means CPU accounting is cheap everywhere without
requiring any controller, hence just remove the directive.
The method is deprecated since 64f173324e
(v257) and announced that it will be removed in v258.
Let's remove it now.
This effectively reverts 84c01612de.
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Morteza Pourkazemi
Luca Boccassi
Lennart Poettering
Luca BoccassiandMichal Koutný
Michael Vogt
Matteo Croce
Michal Sekletar
glemco
Simon Lucido
Daan De Meyer
Nikolas Kyx
Mike Yuan
Usama Arif
Luiz Amaral
seidlerv
Quentin Deslandes
Daan De Meyer
Brett Holman
Lennart Poettering
Grimmauld
Andres Beltran