Age | Commit message (Collapse) | Author |
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This patch set adds full support the new unified cgroup hierarchy logic
of modern kernels.
A new kernel command line option "systemd.unified_cgroup_hierarchy=1" is
added. If specified the unified hierarchy is mounted to /sys/fs/cgroup
instead of a tmpfs. No further hierarchies are mounted. The kernel
command line option defaults to off. We can turn it on by default as
soon as the kernel's APIs regarding this are stabilized (but even then
downstream distros might want to turn this off, as this will break any
tools that access cgroupfs directly).
It is possibly to choose for each boot individually whether the unified
or the legacy hierarchy is used. nspawn will by default provide the
legacy hierarchy to containers if the host is using it, and the unified
otherwise. However it is possible to run containers with the unified
hierarchy on a legacy host and vice versa, by setting the
$UNIFIED_CGROUP_HIERARCHY environment variable for nspawn to 1 or 0,
respectively.
The unified hierarchy provides reliable cgroup empty notifications for
the first time, via inotify. To make use of this we maintain one
manager-wide inotify fd, and each cgroup to it.
This patch also removes cg_delete() which is unused now.
On kernel 4.2 only the "memory" controller is compatible with the
unified hierarchy, hence that's the only controller systemd exposes when
booted in unified heirarchy mode.
This introduces a new enum for enumerating supported controllers, plus a
related enum for the mask bits mapping to it. The core is changed to
make use of this everywhere.
This moves PID 1 into a new "init.scope" implicit scope unit in the root
slice. This is necessary since on the unified hierarchy cgroups may
either contain subgroups or processes but not both. PID 1 hence has to
move out of the root cgroup (strictly speaking the root cgroup is the
only one where processes and subgroups are still allowed, but in order
to support containers nicey, we move PID 1 into the new scope in all
cases.) This new unit is also used on legacy hierarchy setups. It's
actually pretty useful on all systems, as it can then be used to filter
journal messages coming from PID 1, and so on.
The root slice ("-.slice") is now implicitly created and started (and
does not require a unit file on disk anymore), since
that's where "init.scope" is located and the slice needs to be started
before the scope can.
To check whether we are in unified or legacy hierarchy mode we use
statfs() on /sys/fs/cgroup. If the .f_type field reports tmpfs we are in
legacy mode, if it reports cgroupfs we are in unified mode.
This patch set carefuly makes sure that cgls and cgtop continue to work
as desired.
When invoking nspawn as a service it will implicitly create two
subcgroups in the cgroup it is using, one to move the nspawn process
into, the other to move the actual container processes into. This is
done because of the requirement that cgroups may either contain
processes or other subgroups.
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It's cheaper that going to cgroupfs, and also usually the better choice
since it's not racy and can map PIDs even if they were moved to a
different unit.
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In all cases where the function (or cg_is_empty_recursive()) ignoring
the calling process is actually wrong, as a process keeps a cgroup busy
regardless if its the current one or another. Hence, let's simplify
things and drop the "ignore_self" parameter.
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The legacy cgroup hierarchy does not support reliable empty
notifications in containers and if there are left-over subgroups in a
cgroup. This makes it hard to correctly wait for them running empty, and
thus we previously disabled this logic entirely.
With this change we explicitly check for the container case, and whether
the unit is a "delegation" unit (i.e. one where programs may create
their own subgroups). If we are neither in a container, nor operating on
a delegation unit cgroup empty notifications become reliable and thus we
start waiting for the empty notifications again.
This doesn't really fix the general problem around cgroup notifications
but reduces the effect around it.
(This also reorders #include lines by their focus, as suggsted in
CODING_STYLE. We have to add "virt.h", so let's do that at the right
place.)
Also see #317.
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It's primarily just a property of the Manager object after all, and we
try to refer to PID 1 as "manager" instead of "systemd", hence let's to
stick to this here too.
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This adds support for showing the accumulated consumed CPU time per-unit
in the "systemctl status" output. The property is also readable via the
bus.
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https://github.com/docker/docker/issues/10280
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systemd[1]: Failed to set memory.limit_in_bytes on : Invalid argument
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mounted read-only
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for leaf units
Otherwise a slice or delegation unit might move PIDs around ignoring the
fact that it is attached to a subcgroup.
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it's not quite as destructive as it sounds nowadays
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If a cgroup fails to be destroyed (most likely because there are still
processes running as part of a service after the main pid exits), don't
free and remove the cgroup unit from the manager. This fixes a
regression introduced by the cgroup rework in v205 where systemd would
forget about processes still running after the unit becomes inactive.
(This can happen when the main pid exits and KillMode=process or none).
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Using the same scripts as in f647962d64e "treewide: yet more log_*_errno
+ return simplifications".
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If the format string contains %m, clearly errno must have a meaningful
value, so we might as well use log_*_errno to have ERRNO= logged.
Using:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\((".*%m.*")/log_\1_errno(errno, \2/'
Plus some whitespace, linewrap, and indent adjustments.
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It corrrectly handles both positive and negative errno values.
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As a followup to 086891e5c1 "log: add an "error" parameter to all
low-level logging calls and intrdouce log_error_errno() as log calls
that take error numbers", use sed to convert the simple cases to use
the new macros:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\("(.*)%s"(.*), strerror\(-([a-zA-Z_]+)\)\);/log_\1_errno(-\4, "\2%m"\3);/'
Multi-line log_*() invocations are not covered.
And we also should add log_unit_*_errno().
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subhierarchies
For priviliged units this resource control property ensures that the
processes have all controllers systemd manages enabled.
For unpriviliged services (those with User= set) this ensures that
access rights to the service cgroup is granted to the user in question,
to create further subgroups. Note that this only applies to the
name=systemd hierarchy though, as access to other controllers is not
safe for unpriviliged processes.
Delegate=yes should be set for container scopes where a systemd instance
inside the container shall manage the hierarchies below its own cgroup
and have access to all controllers.
Delegate=yes should also be set for user@.service, so that systemd
--user can run, controlling its own cgroup tree.
This commit changes machined, systemd-nspawn@.service and user@.service
to set this boolean, in order to ensure that container management will
just work, and the user systemd instance can run fine.
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systemctl would print 'CPUQuotaPerSecUSec=(null)' for no limit. This
does not look right.
Since USEC_INFINITY is one of the valid values, format_timespan()
could return NULL, and we should wrap every use of it in strna() or
similar. But most callers didn't do that, and it seems more robust to
return a string ("infinity") that makes sense most of the time, even
if in some places the result will not be grammatically correct.
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We'll stay in "initializing" until basic.target has reached, at which
point we will enter "starting".
This is preparation so that we can change the startip timeout to only
apply to the first phase of startup, not the full procedure.
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Also add a bit of debugging output to help diagnose problems,
add missing units, and simplify cppflags.
Move test-engine to normal tests from manual tests, it should now
work without destroying the system.
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Only accept cpu quota values in percentages, get rid of period
definition.
It's not clear whether the CFS period controllable per-cgroup even has a
future in the kernel, hence let's simplify all this, hardcode the period
to 100ms and only accept percentage based quota values.
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This is the behaviour the kernel cgroup rework exposes for all
controllers, hence let's do this already now for all cases.
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Introduce a (unsigned long) -1 as "unset" state for cpu shares/block io
weights, and keep the startup unit set around all the time.
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Similar to CPUShares= and BlockIOWeight= respectively. However only
assign the specified weight during startup. Each control group
attribute is re-assigned as weight by CPUShares=weight and
BlockIOWeight=weight after startup. If not CPUShares= or
BlockIOWeight= be specified, then the attribute is re-assigned to each
default attribute value. (default cpu.shares=1024, blkio.weight=1000)
If only CPUShares=weight or BlockIOWeight=weight be specified, then
that implies StartupCPUShares=weight and StartupBlockIOWeight=weight.
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We should no longer pretend that we can run in any sensible way
without the kernel supporting us with cgroups functionality.
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if PrivateDevices=yes is used we need to make sure we can still
create /dev/null and so on.
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safe_close() automatically becomes a NOP when a negative fd is passed,
and returns -1 unconditionally. This makes it easy to write lines like
this:
fd = safe_close(fd);
Which will close an fd if it is open, and reset the fd variable
correctly.
By making use of this new scheme we can drop a > 200 lines of code that
was required to test for non-negative fds or to reset the closed fd
variable afterwards.
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hence don't bother
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particular devices nodes
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Resolve spotted issues related to missing or extraneous commas, dashes.
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enabled when enabling/disabling cgroup controllers for units
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Previously a cgroup setting down tree would result in cgroup membership
additions being propagated up the tree and to the siblings, however a
unit could never lose cgroup memberships again. With this change we'll
make sure that both cgroup additions and removals propagate properly.
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If the unit already was in the hashmap, path would be leaked.
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