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path: root/src/basic/cgroup-util.h
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2017-02-22Rename cg_is_unified_systemd_controller_wanted to cg_is_hybrid_wantedZbigniew Jędrzejewski-Szmek
Less typing and doesn't make the table so incredibly wide.
2017-02-20core: make hybrid cgroup unified mode keep compat /sys/fs/cgroup/systemd ↵Tejun Heo
hierarchy Currently the hybrid mode mounts cgroup v2 on /sys/fs/cgroup instead of the v1 name=systemd hierarchy. While this works fine for systemd itself, it breaks tools which expect cgroup v1 hierarchy on /sys/fs/cgroup/systemd. This patch updates the hybrid mode so that it mounts v2 hierarchy on /sys/fs/cgroup/unified and keeps v1 "name=systemd" hierarchy on /sys/fs/cgroup/systemd for compatibility. systemd itself doesn't depend on the "name=systemd" hierarchy at all. All operations take place on the v2 hierarchy as before but the v1 hierarchy is kept in sync so that any tools which expect it to be there can keep doing so. This allows systemd to take advantage of cgroup v2 process management without requiring other tools to be aware of the hybrid mode. The hybrid mode is implemented by mapping the special systemd controller to /sys/fs/cgroup/unified and making the basic cgroup utility operations - cg_attach(), cg_create(), cg_rmdir() and cg_trim() - also operate on the /sys/fs/cgroup/systemd hierarchy whenever the cgroup2 hierarchy is updated. While a bit messy, this will allow dropping complications from using cgroup v1 for process management a lot sooner than otherwise possible which should make it a net gain in terms of maintainability. v2: Fixed !cgns breakage reported by @evverx and renamed the unified mount point to /sys/fs/cgroup/unified as suggested by @brauner. v3: chown the compat hierarchy too on delegation. Suggested by @evverx. v4: [zj] - drop the change to default, full "legacy" is still the default.
2017-02-18core: simplify cg_[all_]unified()Tejun Heo
cg_[all_]unified() test whether a specific controller or all controllers are on the unified hierarchy. While what's being asked is a simple binary question, the callers must assume that the functions may fail any time, which unnecessarily complicates their usages. This complication is unnecessary. Internally, the test result is cached anyway and there are only a few places where the test actually needs to be performed. This patch simplifies cg_[all_]unified(). * cg_[all_]unified() are updated to return bool. If the result can't be decided, assertion failure is triggered. Error handlings from their callers are dropped. * cg_unified_flush() is updated to calculate the new result synchrnously and return whether it succeeded or not. Places which need to flush the test result are updated to test for failure. This ensures that all the following cg_[all_]unified() tests succeed. * Places which expected possible cg_[all_]unified() failures are updated to call and test cg_unified_flush() before calling cg_[all_]unified(). This includes functions used while setting up mounts during boot and manager_setup_cgroup().
2016-10-13nspawn: cleanup and chown the synced cgroup hierarchy (#4223)Evgeny Vereshchagin
Fixes: #4181
2016-10-07core: add "invocation ID" concept to service managerLennart Poettering
This adds a new invocation ID concept to the service manager. The invocation ID identifies each runtime cycle of a unit uniquely. A new randomized 128bit ID is generated each time a unit moves from and inactive to an activating or active state. The primary usecase for this concept is to connect the runtime data PID 1 maintains about a service with the offline data the journal stores about it. Previously we'd use the unit name plus start/stop times, which however is highly racy since the journal will generally process log data after the service already ended. The "invocation ID" kinda matches the "boot ID" concept of the Linux kernel, except that it applies to an individual unit instead of the whole system. The invocation ID is passed to the activated processes as environment variable. It is additionally stored as extended attribute on the cgroup of the unit. The latter is used by journald to automatically retrieve it for each log logged message and attach it to the log entry. The environment variable is very easily accessible, even for unprivileged services. OTOH the extended attribute is only accessible to privileged processes (this is because cgroupfs only supports the "trusted." xattr namespace, not "user."). The environment variable may be altered by services, the extended attribute may not be, hence is the better choice for the journal. Note that reading the invocation ID off the extended attribute from journald is racy, similar to the way reading the unit name for a logging process is. This patch adds APIs to read the invocation ID to sd-id128: sd_id128_get_invocation() may be used in a similar fashion to sd_id128_get_boot(). PID1's own logging is updated to always include the invocation ID when it logs information about a unit. A new bus call GetUnitByInvocationID() is added that allows retrieving a bus path to a unit by its invocation ID. The bus path is built using the invocation ID, thus providing a path for referring to a unit that is valid only for the current runtime cycleof it. Outlook for the future: should the kernel eventually allow passing of cgroup information along AF_UNIX/SOCK_DGRAM messages via a unique cgroup id, then we can alter the invocation ID to be generated as hash from that rather than entirely randomly. This way we can derive the invocation race-freely from the messages.
2016-08-19Merge pull request #3965 from htejun/systemd-controller-on-unifiedZbigniew Jędrzejewski-Szmek
2016-08-18logind: update empty and "infinity" handling for [User]TasksMax (#3835)Tejun Heo
The parsing functions for [User]TasksMax were inconsistent. Empty string and "infinity" were interpreted as no limit for TasksMax but not accepted for UserTasksMax. Update them so that they're consistent with other knobs. * Empty string indicates the default value. * "infinity" indicates no limit. While at it, replace opencoded (uint64_t) -1 with CGROUP_LIMIT_MAX in TasksMax handling. v2: Update empty string to indicate the default value as suggested by Zbigniew Jędrzejewski-Szmek. v3: Fixed empty UserTasksMax handling.
2016-08-17core: use the unified hierarchy for the systemd cgroup controller hierarchyTejun Heo
Currently, systemd uses either the legacy hierarchies or the unified hierarchy. When the legacy hierarchies are used, systemd uses a named legacy hierarchy mounted on /sys/fs/cgroup/systemd without any kernel controllers for process management. Due to the shortcomings in the legacy hierarchy, this involves a lot of workarounds and complexities. Because the unified hierarchy can be mounted and used in parallel to legacy hierarchies, there's no reason for systemd to use a legacy hierarchy for management even if the kernel resource controllers need to be mounted on legacy hierarchies. It can simply mount the unified hierarchy under /sys/fs/cgroup/systemd and use it without affecting other legacy hierarchies. This disables a significant amount of fragile workaround logics and would allow using features which depend on the unified hierarchy membership such bpf cgroup v2 membership test. In time, this would also allow deleting the said complexities. This patch updates systemd so that it prefers the unified hierarchy for the systemd cgroup controller hierarchy when legacy hierarchies are used for kernel resource controllers. * cg_unified(@controller) is introduced which tests whether the specific controller in on unified hierarchy and used to choose the unified hierarchy code path for process and service management when available. Kernel controller specific operations remain gated by cg_all_unified(). * "systemd.legacy_systemd_cgroup_controller" kernel argument can be used to force the use of legacy hierarchy for systemd cgroup controller. * nspawn: By default nspawn uses the same hierarchies as the host. If UNIFIED_CGROUP_HIERARCHY is set to 1, unified hierarchy is used for all. If 0, legacy for all. * nspawn: arg_unified_cgroup_hierarchy is made an enum and now encodes one of three options - legacy, only systemd controller on unified, and unified. The value is passed into mount setup functions and controls cgroup configuration. * nspawn: Interpretation of SYSTEMD_CGROUP_CONTROLLER to the actual mount option is moved to mount_legacy_cgroup_hierarchy() so that it can take an appropriate action depending on the configuration of the host. v2: - CGroupUnified enum replaces open coded integer values to indicate the cgroup operation mode. - Various style updates. v3: Fixed a bug in detect_unified_cgroup_hierarchy() introduced during v2. v4: Restored legacy container on unified host support and fixed another bug in detect_unified_cgroup_hierarchy().
2016-08-15core: rename cg_unified() to cg_all_unified()Tejun Heo
A following patch will update cgroup handling so that the systemd controller (/sys/fs/cgroup/systemd) can use the unified hierarchy even if the kernel resource controllers are on the legacy hierarchies. This would require distinguishing whether all controllers are on cgroup v2 or only the systemd controller is. In preparation, this patch renames cg_unified() to cg_all_unified(). This patch doesn't cause any functional changes.
2016-08-07core: add cgroup CPU controller support on the unified hierarchyTejun Heo
Unfortunately, due to the disagreements in the kernel development community, CPU controller cgroup v2 support has not been merged and enabling it requires applying two small out-of-tree kernel patches. The situation is explained in the following documentation. https://git.kernel.org/cgit/linux/kernel/git/tj/cgroup.git/tree/Documentation/cgroup-v2-cpu.txt?h=cgroup-v2-cpu While it isn't clear what will happen with CPU controller cgroup v2 support, there are critical features which are possible only on cgroup v2 such as buffered write control making cgroup v2 essential for a lot of workloads. This commit implements systemd CPU controller support on the unified hierarchy so that users who choose to deploy CPU controller cgroup v2 support can easily take advantage of it. On the unified hierarchy, "cpu.weight" knob replaces "cpu.shares" and "cpu.max" replaces "cpu.cfs_period_us" and "cpu.cfs_quota_us". [Startup]CPUWeight config options are added with the usual compat translation. CPU quota settings remain unchanged and apply to both legacy and unified hierarchies. v2: - Error in man page corrected. - CPU config application in cgroup_context_apply() refactored. - CPU accounting now works on unified hierarchy.
2016-07-25Merge pull request #3589 from brauner/cgroup_namespaceLennart Poettering
Cgroup namespace
2016-07-20core: when forcibly killing/aborting left-over unit processes log about itLennart Poettering
Let's lot at LOG_NOTICE about any processes that we are going to SIGKILL/SIGABRT because clean termination of them didn't work. This turns the various boolean flag parameters to cg_kill(), cg_migrate() and related calls into a single binary flags parameter, simply because the function now gained even more parameters and the parameter listed shouldn't get too long. Logging for killing processes is done either when the kill signal is SIGABRT or SIGKILL, or on explicit request if KILL_TERMINATE_AND_LOG instead of LOG_TERMINATE is passed. This isn't used yet in this patch, but is made use of in a later patch.
2016-07-09cgroup: detect cgroup namespacesChristian Brauner
- define CLONE_NEWCGROUP - add fun to detect whether cgroup namespaces are supported
2016-05-18core: add support for IOReadIOPSMax and IOWriteIOPSMaxTejun Heo
cgroup IO controller supports maximum limits for both bandwidth and IOPS but systemd resource control currently only supports bandwidth limits. This patch adds support for IOReadIOPSMax and IOWriteIOPSMax when unified cgroup hierarchy is in use. It isn't difficult to also add BlockIOReadIOPS and BlockIOWriteIOPS for legacy hierarchies but IO control on legacy hierarchies is half-broken anyway, so let's leave it alone for now.
2016-05-18core: introduce CGroupIOLimitType enumsTejun Heo
Currently, there are two cgroup IO limits, bandwidth max for read and write, and they are hard-coded in various places. This is fine for two limits but IO is expected to grow more limits - low, high and max limits for bandwidth and IOPS - and hard-coding each limit won't make sense. This patch replaces hard-coded limits with an array indexed by CGroupIOLimitType and accompanying string and default value tables so that new limits can be added trivially.
2016-05-05core: add io controller support on the unified hierarchyTejun Heo
On the unified hierarchy, blkio controller is renamed to io and the interface is changed significantly. * blkio.weight and blkio.weight_device are consolidated into io.weight which uses the standardized weight range [1, 10000] with 100 as the default value. * blkio.throttle.{read|write}_{bps|iops}_device are consolidated into io.max. Expansion of throttling features is being worked on to support work-conserving absolute limits (io.low and io.high). * All stats are consolidated into io.stats. This patchset adds support for the new interface. As the interface has been revamped and new features are expected to be added, it seems best to treat it as a separate controller rather than trying to expand the blkio settings although we might add automatic translation if only blkio settings are specified. * io.weight handling is mostly identical to blkio.weight[_device] handling except that the weight range is different. * Both read and write bandwidth settings are consolidated into CGroupIODeviceLimit which describes all limits applicable to the device. This makes it less painful to add new limits. * "max" can be used to specify the maximum limit which is equivalent to no config for max limits and treated as such. If a given CGroupIODeviceLimit doesn't contain any non-default configs, the config struct is discarded once the no limit config is applied to cgroup. * lookup_blkio_device() is renamed to lookup_block_device(). Signed-off-by: Tejun Heo <htejun@fb.com>
2016-03-26core: update populated event handling in unified hierarchyTejun Heo
Earlier during the development of unified hierarchy, the populated event was reported through by the dedicated "cgroup.populated" file; however, the interface was updated so that it's reported through the "populated" field of "cgroup.events" file. Update populated event handling logic accordingly.
2016-02-10cgroup: remove support for NetClass= directiveDaniel Mack
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.
2016-02-10tree-wide: remove Emacs lines from all filesDaniel Mack
This should be handled fine now by .dir-locals.el, so need to carry that stuff in every file.
2015-12-01basic: re-sort includesThomas Hindoe Paaboel Andersen
My previous patch to only include what we use accidentially placed the added inlcudes in non-sorted order.
2015-11-30basic: include only what we useThomas Hindoe Paaboel Andersen
This is a cleaned up result of running iwyu but without forward declarations on src/basic.
2015-11-18tree-wide: sort includes in *.hThomas Hindoe Paaboel Andersen
This is a continuation of the previous include sort patch, which only sorted for .c files.
2015-09-16cgroup: add support for net_cls controllersDaniel Mack
Add a new config directive called NetClass= to CGroup enabled units. Allowed values are positive numbers for fix assignments and "auto" for picking a free value automatically, for which we need to keep track of dynamically assigned net class IDs of units. Introduce a hash table for this, and also record the last ID that was given out, so the allocator can start its search for the next 'hole' from there. This could eventually be optimized with something like an irb. The class IDs up to 65536 are considered reserved and won't be assigned automatically by systemd. This barrier can be made a config directive in the future. Values set in unit files are stored in the CGroupContext of the unit and considered read-only. The actually assigned number (which may have been chosen dynamically) is stored in the unit itself and is guaranteed to remain stable as long as the unit is active. In the CGroup controller, set the configured CGroup net class to net_cls.classid. Multiple unit may share the same net class ID, and those which do are linked together.
2015-09-11core: refactor cpu shares/blockio weight cgroup logicLennart Poettering
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.
2015-09-10core: add support for the "pids" cgroup controllerLennart Poettering
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.
2015-09-08cgroups: make sure the "devices" controller's enum is named the same way as ↵Lennart Poettering
the controller in the kernel Follow-up to 5bf8002a3a6723ce50331c024122078552fb600a.
2015-09-01core: unified cgroup hierarchy supportLennart Poettering
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.
2015-09-01cgroup: drop "ignore_self" argument from cg_is_empty()Lennart Poettering
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.
2015-06-11build-sys: split internal basic/ library from shared/Kay Sievers
basic/ can be used by everything cannot use anything outside of basic/ libsystemd/ can use basic/ cannot use shared/ shared/ can use libsystemd/