This adds a new per-service OOMPolicy= (along with a global
DefaultOOMPolicy=) that controls what to do if a process of the service
is killed by the kernel's OOM killer. It has three different values:
"continue" (old behaviour), "stop" (terminate the service), "kill" (let
the kernel kill all the service's processes).
On top of that, track OOM killer events per unit: generate a per-unit
structured, recognizable log message when we see an OOM killer event,
and put the service in a failure state if an OOM killer event was seen
and the selected policy was not "continue". A new "result" is defined
for this case: "oom-kill".
All of this relies on new cgroupv2 kernel functionality: the
"memory.events" notification interface and the "memory.oom.group"
attribute (which makes the kernel kill all cgroup processes
automatically).
Building on previous commit, let's pass the unit name when parsing
dbus message or builtin whitelist, which is better than nothing.
seccomp_parse_syscall_filter() is not needed anymore, so it is removed,
and seccomp_parse_syscall_filter_full() is renamed to take its place.
We are about to add system calls (rseq()) not available on old
libseccomp/old kernels, and hence we need to be permissive when parsing
our definitions.
This new setting allows configuration of CFS period on the CPU cgroup, instead
of using a hardcoded default of 100ms.
Tested:
- Legacy cgroup + Unified cgroup
- systemctl set-property
- systemctl show
- Confirmed that the cgroup settings (such as cpu.cfs_period_ns) were set
appropriately, including updating the CPU quota (cpu.cfs_quota_ns) when
CPUQuotaPeriodSec= is updated.
- Checked that clamping works properly when either period or (quota * period)
are below the resolution of 1ms, or if period is above the max of 1s.
ensure that mfree() on filename is called after the logging function
which uses the string pointed by filename
Signed-off-by: Khem Raj <raj.khem@gmail.com>
fdopen doesn't accept "e", it's ignored. Let's not mislead people into
believing that it actually sets O_CLOEXEC.
From `man 3 fdopen`:
> e (since glibc 2.7):
> Open the file with the O_CLOEXEC flag. See open(2) for more information. This flag is ignored for fdopen()
As mentioned by @jlebon in #11131.
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.
add new "systemd-run-generator" for running arbitrary commands from the kernel command line as system services using the "systemd.run=" kernel command line switch
This adds SuccessActionExitStatus= and FailureActionExitStatus= that may
be used to configure the exit status to propagate in when
SuccessAction=exit or FailureAction=exit is used.
When not specified let's also propagate the exit status of the main
process we fork off for the unit.
In a way this is a follow-up for
a2d1fb882c, but adds a similar warning for
PIDFile=.
There's a much stronger case for doing this kind of notification in
tmpfiles.d (since it helps relating lines to each other for the purpose
of merging them). Doing this for PIDFile= is mostly about being
systematic and copying tmpfiles.d/ behaviour here.
While we are at it, let's also support relative filenames in PIDFile=
now, and prefix them with /run, to make them absolute.
Fixes: #10657
Before we would only accept those "system" values, so there wasn't other
chocie. Let's provide backwards compatiblity in case somebody made use of
this functionality in user mode.
v2: use 'exit-force' not 'exit'
v3: use error value in log_syntax
We would accept e.g. FailureAction=reboot-force in user units and then do an
exit in the user manager. Let's be stricter, and define "exit"/"exit-force" as
the only supported actions in user units.
v2:
- rename 'exit' to 'exit-force' and add new 'exit'
- add test for the parsing function
We so far had various placed we'd parse percentages with
parse_percent(). Let's make them use parse_permille() instead, which is
downward compatible (as it also parses percent values), and increases
the granularity a bit. Given that on the wire we usually normalize
relative specifications to something like UINT32_MAX anyway changing
from base-100 to base-1000 calculations can be done easily without
breaking compat.
This commit doesn't document this change in the man pages. While
allowing more precise specifcations permille is not as commonly
understood as perent I guess, hence let's keep this out of the docs for
now.
The kernel added support for a new cgroup memory controller knob memory.min in
bf8d5d52ffe8 ("memcg: introduce memory.min") which was merged during v4.18
merge window.
Add MemoryMin to support memory.min.
The functions protect_{home,system}_from_string() are not used
except for defining protect_{home,system}_or_bool_from_string().
This makes protect_{home,system}_from_string() support boolean
strings, and drops protect_{home,system}_or_bool_from_string().
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
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.
This drops needless safety checks that ensure we only reference block
devices for blockio/io settings. The backing code was already able to
accept regular file system paths too, in which case the backing device
node of that file system would be used. Hence, let's drop the artificial
restrictions and open up this underlying functionality.
The function is similar to path_kill_slashes() but also removes
initial './', trailing '/.', and '/./' in the path.
When the second argument of path_simplify() is false, then it
behaves as the same as path_kill_slashes(). Hence, this also
replaces path_kill_slashes() with path_simplify().
