To make sure everything still compiles, we add a preliminary include
of forward.h to tests.h to make sure it is included in every test source
file. We'll clean up the tests.h includes in a later commit.
We also add a <errno.h> include to errno-list.h to keep test-errno-list.c
compiling. It'll be removed again when we clean up includes in src/basic.
Split out of #37344.
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.
We generally prefer dealing with parsed data instead of original
strings, do so for the "rwm" strings too. We have to convert this to
flags for the primary backend implementation (BPF) anyway, hence we
can do this early to have simpler, shorter and more normalized code.
Almost all our enums/structs/funcs carry the CGroup prefix if they are
defined in cgroup.h, TasksMax so far does not, even though it is
exclusively used in cgroup context.
Change that.
This adds a new structure UnitDefaults which embedds the various default
settings for units we maintain. We so far maintained two sets of
variables for this, one in main.c as static variables and one in the
Manager structure. This moves them into a common structure.
This is most just search/replace, i.e. very dumb refactoring.
The fact that we now use a common structure for this allows us further
refactorings later.
Inspired by the discussions on #27890
In various tools and services we have a per-system and per-user concept.
So far we sometimes used a boolean indicating whether we are in system
mode, or a reversed boolean indicating whether we are in user mode, or
the LookupScope enum used by the lookup path logic.
Let's address that, in introduce a common enum for this, we can use all
across the board.
This is mostly just search/replace, no actual code changes.
Note that test-cgroup-mask, test-cgroup-unit-default and test-unit-name will now
report being skipped instead of reporting success if not run under systemd.
-------------------------------------------------------------------------------
Example Run:
foobar.service created below is a service unit file that has a non-existing key-value
pairing (foo = bar) and is thus, syntactically invalid.
maanya-goenka@debian:~/systemd (img-support)$ cat <<EOF>img/usr/lib/systemd/system/foobar.service
> [Unit]
> foo = bar
>
> [Service]
> ExecStart = /opt/script0.sh
> EOF
The failure to create foobar.service because of the recursive dependency searching and verification has been addressed
in a different PR: systemd-analyze: add option to return an error value when unit verification fails #20233
maanya-goenka@debian:~/systemd (img-support)$ sudo build/systemd-analyze verify --root=img/ foobar.service
/home/maanya-goenka/systemd/img/usr/lib/systemd/system/foobar.service:2: Unknown key name 'foo' in section 'Unit', ignoring.
foobar.service: Failed to create foobar.service/start: Unit sysinit.target not found.
In a later commit we intend to move the slice logic to use proper
dependencies instead of a "UnitRef" object. This preparatory commit
drops direct use of the slice UnitRef object for a static inline
function UNIT_GET_SLICE() that is both easier to grok, and allows us to
easily replace its internal implementation later on.
The usage in unit_get_own_mask is redundant, we only need apply
disable_mask at the end befor application, i.e. calculating enable or
target mask.
(IOW, we allow all configurations, but disabling affects effective
controls.)
Modify tests accordingly and add testing of enable mask.
This is intended as cleanup, with no effect but changing unit_dump
output.
TasksMax= and DefaultTasksMax= can be specified as percentages. We don't
actually document of what the percentage is relative to, but the implementation
uses the smallest of /proc/sys/kernel/pid_max, /proc/sys/kernel/threads-max,
and /sys/fs/cgroup/pids.max (when present). When the value is a percentage,
we immediately convert it to an absolute value. If the limit later changes
(which can happen e.g. when systemd-sysctl runs), the absolute value becomes
outdated.
So let's store either the percentage or absolute value, whatever was specified,
and only convert to an absolute value when the value is used. For example, when
starting a unit, the absolute value will be calculated when the cgroup for
the unit is created.
Fixes#13419.
Introduce support for configuring cpus and mems for processes using
cgroup v2 CPUSET controller. This allows users to limit which cpus
and memory NUMA nodes can be used by processes to better utilize
system resources.
The cgroup v2 interfaces to control it are cpuset.cpus and cpuset.mems
where the requested configuration is written. However, it doesn't mean
that the requested configuration will be actually used as parent cgroup
may limit the cpus or mems as well. In order to reflect the real
configuration cgroup v2 provides read-only files cpuset.cpus.effective
and cpuset.mems.effective which are exported to users as well.
Some controllers (like the CPU controller) have a performance cost that
is non-trivial on certain workloads. While this can be mitigated and
improved to an extent, there will for some controllers always be some
overheads associated with the benefits gained from the controller.
Inside Facebook, the fix applied has been to disable the CPU controller
forcibly with `cgroup_disable=cpu` on the kernel command line.
This presents a problem: to disable or reenable the controller, a reboot
is required, but this is quite cumbersome and slow to do for many
thousands of machines, especially machines where disabling/enabling a
stateful service on a machine is a matter of several minutes.
Currently systemd provides some configuration knobs for these in the
form of `[Default]CPUAccounting`, `[Default]MemoryAccounting`, and the
like. The limitation of these is that Default*Accounting is overrideable
by individual services, of which any one could decide to reenable a
controller within the hierarchy at any point just by using a controller
feature implicitly (eg. `CPUWeight`), even if the use of that CPU
feature could just be opportunistic. Since many services are provided by
the distribution, or by upstream teams at a particular organisation,
it's not a sustainable solution to simply try to find and remove
offending directives from these units.
This commit presents a more direct solution -- a DisableControllers=
directive that forcibly disallows a controller from being enabled within
a subtree.
systemd only uses functions that are as of Linux 4.15+ provided
externally to the CPU controller (currently usage_usec), so if we have a
new enough kernel, we don't need to set CGROUP_MASK_CPU for
CPUAccounting=true as the CPU controller does not need to necessarily be
enabled in this case.
Part of this patch is modelled on an earlier patch by Ryutaroh Matsumoto
(see PR #9665).
Cgroup v2 provides the eBPF-based device controller, which isn't currently
supported by systemd. This commit aims to provide such support.
There are no user-visible changes, just the device policy and whitelist
start working if cgroup v2 is used.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Doing manager_load_unit() followed by UNIT_VTABLE(unit)->start(unit) would
result in an assertion failure in ->start() if the unit failed to load
properly. Something like this is okey-ish is tests, since the test units are
not expected to fail to load, but the reason for failure is clearer if we
fail immediately.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
When running tests like test-unit-name, there is not point in setting
up the cgroup and signals and interacting with the environment. Similarly
when running fuzz testing of the parser.
Add new MANAGER_TEST_RUN_BASIC which takes the role of MANAGER_TEST_RUN_MINIMAL,
and redefine MANAGER_TEST_RUN_MINIMAL to just create the basic data structures.
Luiz Amaral
Yu Watanabe
Mike Yuan
Daan De Meyer
Ivan Kruglov
Usman Akinyemi
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Jan Janssen
Mauricio Vásquez
Maanya Goenka
Julia Kartseva
Michal Koutný
Pavel Hrdina
Chris Down
Roman Gushchin
Filipe Brandenburger