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2016-08-19Merge pull request #3965 from htejun/systemd-controller-on-unifiedZbigniew Jędrzejewski-Szmek
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
2016-07-20cgroup: suppress sending follow-up SIGCONT after sending SIGCONT/SIGKILL anywayLennart Poettering
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.
2016-03-26cgroup2: use new fstype for unified hierarchyAlban Crequy
Since Linux v4.4-rc1, __DEVEL__sane_behavior does not exist anymore and is replaced by a new fstype "cgroup2". With this patch, systemd no longer supports the old (unstable) way of doing unified hierarchy with __DEVEL__sane_behavior and systemd now requires Linux v4.4 for unified hierarchy. Non-unified hierarchy is still the default and is unchanged by this patch. https://github.com/torvalds/linux/commit/67e9c74b8a873408c27ac9a8e4c1d1c8d72c93ff
2016-02-23tree-wide: minor formatting inconsistency cleanupsVito Caputo
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.
2016-01-13tree-wide: check if errno is greater than zero (2)Zbigniew Jędrzejewski-Szmek
Compare errno with zero in a way that tells gcc that (if the condition is true) errno is positive.
2016-01-13tree-wide: check if errno is greater then zeroZbigniew Jędrzejewski-Szmek
gcc is confused by the common idiom of return errno ? -errno : -ESOMETHING and thinks a positive value may be returned. Replace this condition with errno > 0 to help gcc and avoid many spurious warnings. I filed a gcc rfe a long time ago, but it hard to say if it will ever be implemented [1]. Both conventions were used in the codebase, this change makes things more consistent. This is a follow up to bcb161b0230f. [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61846
2016-01-12tree-wide: use xsprintf() where applicableDaniel Mack
Also add a coccinelle receipt to help with such transitions.
2015-12-02tests: turn check if manager cannot be intialized into macroZbigniew Jędrzejewski-Szmek
We need to check the same thing in multiple tests. Use a shared macro to make it easier to update the list of errnos. Change the errno code for "unitialized cgroup fs" for ENOMEDIUM. Exec format error looks like something more serious. This fixes test-execute invocation in mock.
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.
2015-10-27util-lib: split out allocation calls into alloc-util.[ch]Lennart Poettering
2015-10-27stat-util.h: move F_TYPE_EQUAL() macro definition to stat-util.hLennart Poettering
2015-10-27util-lib: move /proc/cmdline parsing code to proc-cmdline.[ch]Lennart Poettering
2015-10-27util-lib: move string table stuff into its own string-table.[ch]Lennart Poettering
2015-10-27util-lib: move a number of fs operations into fs-util.[ch]Lennart Poettering
2015-10-27util-lib: introduce dirent-util.[ch] for directory entry callsLennart Poettering
Also, move a couple of more path-related functions to path-util.c.
2015-10-27util-lib: split string parsing related calls from util.[ch] into parse-util.[ch]Lennart Poettering
2015-10-26util-lib: split out user/group/uid/gid calls into user-util.[ch]Lennart Poettering
2015-10-25util-lib: split out fd-related operations into fd-util.[ch]Lennart Poettering
There are more than enough to deserve their own .c file, hence move them over.
2015-10-24util-lib: split our string related calls from util.[ch] into its own file ↵Lennart Poettering
string-util.[ch] There are more than enough calls doing string manipulations to deserve its own files, hence do something about it. This patch also sorts the #include blocks of all files that needed to be updated, according to the sorting suggestions from CODING_STYLE. Since pretty much every file needs our string manipulation functions this effectively means that most files have sorted #include blocks now. Also touches a few unrelated include files.
2015-10-24util: split out extract_first_word() and related calls into extract-word.[ch]Lennart Poettering
This is quite a lot of code these days, hence move it to its own source file.
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.
2015-09-08cgroup-util: fix devices controllerMartin Pitt
Commit efdb0237 accidentally changed the name of the "devices" cgroup controller to "device".
2015-09-04nspawn: enable all controllers we can for the "payload" subcgroup we createLennart Poettering
In the unified hierarchy delegating controller access is safe, hence make sure to enable all controllers for the "payload" subcgroup if we create it, so that the container will have all controllers enabled the nspawn service itself has.
2015-09-04cgroup: always read the supported controllers from the root cgroup of the ↵Lennart Poettering
local container Otherwise we might end up thinking that we support more controllers than actually enabled for the container we are running in.
2015-09-04cgroup: fix potential access of uninitialized variableLennart Poettering
2015-09-04cgroup-util: make cg_pid_get_path() return -ENODATA when controller can't be ↵Lennart Poettering
found If the controller managed by systemd cannot found in /proc/$PID/cgroup, return ENODATA, the usual error for cases where the data being looked for does not exist, even if the process does.
2015-09-04cgroup: fix potential bad memory accessLennart Poettering
2015-09-04cgroup: make sure cg_is_empty_recursive() returns 1 for non-existing cgroupsLennart Poettering
Previously, on the legacy hierarchy a non-existing cgroup was considered identical to an empty one, but the unified hierarchy the check for a non-existing one returned ENOENT.
2015-09-04cgroup: when comparing agent paths, use path_equal()Lennart Poettering
After all a path is a path is a path and we should use path_equal() to comapre those.
2015-09-04cgroup: move controller to dirname translation into join_path_legacy()Lennart Poettering
Let's simplify things a bit.
2015-09-04macro: introduce new PID_TO_PTR macros and make use of themLennart Poettering
This adds a new PID_TO_PTR() macro, plus PTR_TO_PID() and makes use of it wherever we maintain processes in a hash table. Previously we sometimes used LONG_TO_PTR() and other times ULONG_TO_PTR() for that, hence let's make this more explicit and clean up things.
2015-09-03cg_get_path: Removed unreachable statementreverendhomer
controller cannot be NULL because if-statement in L509 has return Coverity #1322379
2015-09-02tree-wide: fix indentationThomas Hindoe Paaboel Andersen
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.