cgroup: remove support for NetClass= directive Support for net_cls.class_id through the NetClass= configuration directive has been added in v227 in preparation for a per-unit packet filter mechanism. However, it turns out the kernel people have decided to deprecate the net_cls and net_prio controllers in v2. Tejun provides a comprehensive justification for this in his commit, which has landed during the merge window for kernel v4.5: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bd1060a1d671 As we're aiming for full support for the v2 cgroup hierarchy, we can no longer support this feature. Userspace tool such as nftables are moving over to setting rules that are specific to the full cgroup path of a task, which obsoletes these controllers anyway. This commit removes support for tweaking details in the net_cls controller, but keeps the NetClass= directive around for legacy compatibility reasons.

man: document special considerations when mixing templated service units and DefaultDependencies=no Fixes #2189.

core: add new DefaultTasksMax= setting for system.conf This allows initializing the TasksMax= setting of all units by default to some fixed value, instead of leaving it at infinity as before.

man: document automatic dependencies For all units ensure there's an "Automatic Dependencies" section in the man page, and explain which dependencies are automatically added in all cases, and which ones are added on top if DefaultDependencies=yes is set. This is also done for systemd.exec(5), systemd.resource-control(5) and systemd.unit(5) as these pages describe common behaviour of various unit types.

doc: correct punctuation and improve typography in documentation

man: move documentation about NetClass from systemd.unit(5) to systemd.resource-control(5) This is after all where we expose all the other cgroup props, especially those that can be adjusted dynamically.

core: refactor cpu shares/blockio weight cgroup logic Let's stop using the "unsigned long" type for weights/shares, and let's just use uint64_t for this, as that's what we expose on the bus. Unify parsers, and always validate the range for these fields. Correct the default blockio weight to 500, since that's what the kernel actually uses. When parsing the weight/shares settings from unit files accept the empty string as a way to reset the weight/shares value. When getting it via the bus, uniformly map (uint64_t) -1 to unset. Open up StartupCPUShares= and StartupBlockIOWeight= to transient units.

core: add support for the "pids" cgroup controller This adds support for the new "pids" cgroup controller of 4.3 kernels. It allows accounting the number of tasks in a cgroup and enforcing limits on it. This adds two new setting TasksAccounting= and TasksMax= to each unit, as well as a gloabl option DefaultTasksAccounting=. This also updated "cgtop" to optionally make use of the new kernel-provided accounting. systemctl has been updated to show the number of tasks for each service if it is available. This patch also adds correct support for undoing memory limits for units using a MemoryLimit=infinity syntax. We do the same for TasksMax= now and hence keep things in sync here.

man: revert dynamic paths for split-usr setups This did not really work out as we had hoped. Trying to do this upstream introduced several problems that probably makes it better suited as a downstream patch after all. At any rate, it is not releaseable in the current state, so we at least need to revert this before the release. * by adjusting the path to binaries, but not do the same thing to the search path we end up with inconsistent man-pages. Adjusting the search path too would be quite messy, and it is not at all obvious that this is worth the effort, but at any rate it would have to be done before we could ship this. * this means that distributed man-pages does not make sense as they depend on config options, and for better or worse we are still distributing man pages, so that is something that definitely needs sorting out before we could ship with this patch. * we have long held that split-usr is only minimally supported in order to boot, and something we hope will eventually go away. So before we start adding even more magic/effort in order to make this work nicely, we should probably question if it makes sense at all.

man: generate configured paths in manpages In particular, use /lib/systemd instead of /usr/lib/systemd in distributions like Debian which still have not adopted a /usr merge setup. Use XML entities from man/custom-entities.ent to replace configured paths while doing XSLT processing of the original XML files. There was precedent of some files (such as systemd.generator.xml) which were already using this approach. This addresses most of the (manual) fixes from this patch: http://anonscm.debian.org/cgit/pkg-systemd/systemd.git/tree/debian/patches/Fix-paths-in-man-pages.patch?h=experimental-220 The idea of using generic XML entities was presented here: http://lists.freedesktop.org/archives/systemd-devel/2015-May/032240.html This patch solves almost all the issues, with the exception of: - Path to /bin/mount and /bin/umount. - Generic statements about preference of /lib over /etc. These will be handled separately by follow up patches. Tested: - With default configure settings, ran "make install" to two separate directories and compared the output to confirm they matched exactly. - Used a set of configure flags including $CONFFLAGS from Debian: http://anonscm.debian.org/cgit/pkg-systemd/systemd.git/tree/debian/rules Installed the tree and confirmed the paths use /lib/systemd instead of /usr/lib/systemd and that no other unexpected differences exist. - Confirmed that `make distcheck` still passes.

man: boilerplate unification

man: fix typos

man: add emacs header to get correct indention in nxml-mode for the manpage XML files that use 2ch indenting In the long run we really should figure out if we want to stick with 8ch or 2ch indenting, and not continue with half-and-half. For now, just make emacs aware of the files that use 2ch indenting.

core: introduce new Delegate=yes/no property controlling creation of cgroup 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.

man: fix copy/paste error in CPUQuota= section of resource-control

man: reword StartupCPUShares= description Now that we have two options described in the same paragraph, we cannot use singular anymore.

cgroups: simplify CPUQuota= logic 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.

cgroup: rework startup logic Introduce a (unsigned long) -1 as "unset" state for cpu shares/block io weights, and keep the startup unit set around all the time.

core: add startup resource control option 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.

doc: adhere to XML syntax

core: expose CFS CPU time quota as high-level unit properties

core: support globbing matches in DeviceAllow= when checking for device groups

core: add global settings for enabling CPUAccounting=, MemoryAccounting=, BlockIOAccounting= for all units at once

core: clean up some confusing regarding SI decimal and IEC binary suffixes for sizes According to Wikipedia it is customary to specify hardware metrics and transfer speeds to the basis 1000 (SI decimal), while software metrics and physical volatile memory (RAM) sizes to the basis 1024 (IEC binary). So far we specified everything in IEC, let's fix that and be more true to what's otherwise customary. Since we don't want to parse "Mi" instead of "M" we document each time what the context used is.

cgroup: Extend DeviceAllow= syntax to whitelist groups of devices, not just particular devices nodes

man: wording and grammar updates This is a recurring submission and includes corrections to various issue spotted. I guess I can just skip over reporting ubiquitous comma placement fixes…

man: link cgroups api docs from relevant man pages

man: drop references to "cgroup" wher appropriate Since cgroups are mostly now an implementation detail of systemd lets deemphasize it a bit in the man pages. This renames systemd.cgroup(5) to systemd.resource-control(5) and uses the term "resource control" rather than "cgroup" where appropriate. This leaves the word "cgroup" in at a couple of places though, like for example systemd-cgtop and systemd-cgls where cgroup stuff is at the core of what is happening.