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* cgroup, docs: document the root cgroup behavior of cpu and io controllersMaciej S. Szmigiero2018-01-161-1/+35
| | | | | | | | | | | | | | | | | | | Currently, cgroups v2 documentation contains only a generic remark that "How resource consumption in the root cgroup is governed is up to each controller", which isn't really telling users much, who need to dig in the code and / or commit messages to learn the exact behavior. In cgroups v1 at least the blkio controller had its operation with respect to competition between child threads and child cgroups documented in blkio-controller.txt, with references to cfq-iosched.txt. Also, cgroups v2 documentation describes v1 behavior of both cpu and blkio controllers in an "Issues with v1" section. Let's document this behavior also for cgroups v2 to make life easier for users. Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name> Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup-v2.txt: fix typosVladimir Rutsky2018-01-021-4/+4
| | | | | Signed-off-by: Vladimir Rutsky <rutsky@google.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup, docs: document cgroup v2 device controllerRoman Gushchin2017-12-131-4/+29
| | | | | | | | | | | | | Add the corresponding section in cgroup v2 documentation. Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: kernel-team@fb.com Cc: cgroups@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup: add warning about RT not being supported on cgroup2Tejun Heo2017-12-051-0/+7
| | | | | | | | | | | We haven't yet figured out what to do with RT threads on cgroup2. Document the limitation. v2: Included the warning about system management software behavior as suggested by Michael. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
* cgroup, sched: Move basic cpu stats from cgroup.stat to cpu.statTejun Heo2017-10-261-10/+5
| | | | | | | | | | | | | | | | | The basic cpu stat is currently shown with "cpu." prefix in cgroup.stat, and the same information is duplicated in cpu.stat when cpu controller is enabled. This is ugly and not very scalable as we want to expand the coverage of stat information which is always available. This patch makes cgroup core always create "cpu.stat" file and show the basic cpu stat there and calls the cpu controller to show the extra stats when enabled. This ensures that the same information isn't presented in multiple places and makes future expansion of basic stats easier. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
* sched: Implement interface for cgroup unified hierarchyTejun Heo2017-09-291-24/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a couple interface issues which can be addressed in cgroup2 interface. * Stats from cpuacct being reported separately from the cpu stats. * Use of different time units. Writable control knobs use microseconds, some stat fields use nanoseconds while other cpuacct stat fields use centiseconds. * Control knobs which can't be used in the root cgroup still show up in the root. * Control knob names and semantics aren't consistent with other controllers. This patchset implements cpu controller's interface on cgroup2 which adheres to the controller file conventions described in Documentation/cgroups/cgroup-v2.txt. Overall, the following changes are made. * cpuacct is implictly enabled and disabled by cpu and its information is reported through "cpu.stat" which now uses microseconds for all time durations. All time duration fields now have "_usec" appended to them for clarity. Note that cpuacct.usage_percpu is currently not included in "cpu.stat". If this information is actually called for, it will be added later. * "cpu.shares" is replaced with "cpu.weight" and operates on the standard scale defined by CGROUP_WEIGHT_MIN/DFL/MAX (1, 100, 10000). The weight is scaled to scheduler weight so that 100 maps to 1024 and the ratio relationship is preserved - if weight is W and its scaled value is S, W / 100 == S / 1024. While the mapped range is a bit smaller than the orignal scheduler weight range, the dead zones on both sides are relatively small and covers wider range than the nice value mappings. This file doesn't make sense in the root cgroup and isn't created on root. * "cpu.weight.nice" is added. When read, it reads back the nice value which is closest to the current "cpu.weight". When written, it sets "cpu.weight" to the weight value which matches the nice value. This makes it easy to configure cgroups when they're competing against threads in threaded subtrees. * "cpu.cfs_quota_us" and "cpu.cfs_period_us" are replaced by "cpu.max" which contains both quota and period. v4: - Use cgroup2 basic usage stat as the information source instead of cpuacct. v3: - Added "cpu.weight.nice" to allow using nice values when configuring the weight. The feature is requested by PeterZ. - Merge the patch to enable threaded support on cpu and cpuacct. - Dropped the bits about getting rid of cpuacct from patch description as there is a pretty strong case for making cpuacct an implicit controller so that basic cpu usage stats are always available. - Documentation updated accordingly. "cpu.rt.max" section is dropped for now. v2: - cpu_stats_show() was incorrectly using CONFIG_FAIR_GROUP_SCHED for CFS bandwidth stats and also using raw division for u64. Use CONFIG_CFS_BANDWITH and do_div() instead. "cpu.rt.max" is not included yet. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org>
* cgroup: Implement cgroup2 basic CPU usage accountingTejun Heo2017-09-251-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In cgroup1, while cpuacct isn't actually controlling any resources, it is a separate controller due to combination of two factors - 1. enabling cpu controller has significant side effects, and 2. we have to pick one of the hierarchies to account CPU usages on. cpuacct controller is effectively used to designate a hierarchy to track CPU usages on. cgroup2's unified hierarchy removes the second reason and we can account basic CPU usages by default. While we can use cpuacct for this purpose, both its interface and implementation leave a lot to be desired - it collects and exposes two sources of truth which don't agree with each other and some of the exposed statistics don't make much sense. Also, it propagates all the way up the hierarchy on each accounting event which is unnecessary. This patch adds basic resource accounting mechanism to cgroup2's unified hierarchy and accounts CPU usages using it. * All accountings are done per-cpu and don't propagate immediately. It just bumps the per-cgroup per-cpu counters and links to the parent's updated list if not already on it. * On a read, the per-cpu counters are collected into the global ones and then propagated upwards. Only the per-cpu counters which have changed since the last read are propagated. * CPU usage stats are collected and shown in "cgroup.stat" with "cpu." prefix. Total usage is collected from scheduling events. User/sys breakdown is sourced from tick sampling and adjusted to the usage using cputime_adjust(). This keeps the accounting side hot path O(1) and per-cpu and the read side O(nr_updated_since_last_read). v2: Minor changes and documentation updates as suggested by Waiman and Roman. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Waiman Long <longman@redhat.com> Cc: Roman Gushchin <guro@fb.com>
* cgroup: add cgroup.stat interface with basic hierarchy statsRoman Gushchin2017-08-021-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A cgroup can consume resources even after being deleted by a user. For example, writing back dirty pages should be accounted and limited, despite the corresponding cgroup might contain no processes and being deleted by a user. In the current implementation a cgroup can remain in such "dying" state for an undefined amount of time. For instance, if a memory cgroup contains a pge, mlocked by a process belonging to an other cgroup. Although the lifecycle of a dying cgroup is out of user's control, it's important to have some insight of what's going on under the hood. In particular, it's handy to have a counter which will allow to detect css leaks. To solve this problem, add a cgroup.stat interface to the base cgroup control files with the following metrics: nr_descendants total number of visible descendant cgroups nr_dying_descendants total number of dying descendant cgroups Signed-off-by: Roman Gushchin <guro@fb.com> Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: Waiman Long <longman@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: kernel-team@fb.com Cc: cgroups@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org
* cgroup: implement hierarchy limitsRoman Gushchin2017-08-021-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Creating cgroup hierearchies of unreasonable size can affect overall system performance. A user might want to limit the size of cgroup hierarchy. This is especially important if a user is delegating some cgroup sub-tree. To address this issue, introduce an ability to control the size of cgroup hierarchy. The cgroup.max.descendants control file allows to set the maximum allowed number of descendant cgroups. The cgroup.max.depth file controls the maximum depth of the cgroup tree. Both are single value r/w files, with "max" default value. The control files exist on each hierarchy level (including root). When a new cgroup is created, we check the total descendants and depth limits on each level, and if none of them are exceeded, a new cgroup is created. Only alive cgroups are counted, removed (dying) cgroups are ignored. Signed-off-by: Roman Gushchin <guro@fb.com> Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: Waiman Long <longman@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: kernel-team@fb.com Cc: cgroups@vger.kernel.org Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org
* cgroup: remove unnecessary empty check when enabling threaded modeTejun Heo2017-07-251-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | cgroup_enable_threaded() checks that the cgroup doesn't have any tasks or children and fails the operation if so. This test is unnecessary because the first part is already checked by cgroup_can_be_thread_root() and the latter is unnecessary. The latter actually cause a behavioral oddity. Please consider the following hierarchy. All cgroups are domains. A / \ B C \ D If B is made threaded, C and D becomes invalid domains. Due to the no children restriction, threaded mode can't be enabled on C. For C and D, the only thing the user can do is removal. There is no reason for this restriction. Remove it. Acked-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup: implement cgroup v2 thread supportTejun Heo2017-07-211-15/+170
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements cgroup v2 thread support. The goal of the thread mode is supporting hierarchical accounting and control at thread granularity while staying inside the resource domain model which allows coordination across different resource controllers and handling of anonymous resource consumptions. A cgroup is always created as a domain and can be made threaded by writing to the "cgroup.type" file. When a cgroup becomes threaded, it becomes a member of a threaded subtree which is anchored at the closest ancestor which isn't threaded. The threads of the processes which are in a threaded subtree can be placed anywhere without being restricted by process granularity or no-internal-process constraint. Note that the threads aren't allowed to escape to a different threaded subtree. To be used inside a threaded subtree, a controller should explicitly support threaded mode and be able to handle internal competition in the way which is appropriate for the resource. The root of a threaded subtree, the nearest ancestor which isn't threaded, is called the threaded domain and serves as the resource domain for the whole subtree. This is the last cgroup where domain controllers are operational and where all the domain-level resource consumptions in the subtree are accounted. This allows threaded controllers to operate at thread granularity when requested while staying inside the scope of system-level resource distribution. As the root cgroup is exempt from the no-internal-process constraint, it can serve as both a threaded domain and a parent to normal cgroups, so, unlike non-root cgroups, the root cgroup can have both domain and threaded children. Internally, in a threaded subtree, each css_set has its ->dom_cset pointing to a matching css_set which belongs to the threaded domain. This ensures that thread root level cgroup_subsys_state for all threaded controllers are readily accessible for domain-level operations. This patch enables threaded mode for the pids and perf_events controllers. Neither has to worry about domain-level resource consumptions and it's enough to simply set the flag. For more details on the interface and behavior of the thread mode, please refer to the section 2-2-2 in Documentation/cgroup-v2.txt added by this patch. v5: - Dropped silly no-op ->dom_cgrp init from cgroup_create(). Spotted by Waiman. - Documentation updated as suggested by Waiman. - cgroup.type content slightly reformatted. - Mark the debug controller threaded. v4: - Updated to the general idea of marking specific cgroups domain/threaded as suggested by PeterZ. v3: - Dropped "join" and always make mixed children join the parent's threaded subtree. v2: - After discussions with Waiman, support for mixed thread mode is added. This should address the issue that Peter pointed out where any nesting should be avoided for thread subtrees while coexisting with other domain cgroups. - Enabling / disabling thread mode now piggy backs on the existing control mask update mechanism. - Bug fixes and cleanup. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org>
* cgroup: update outdated cgroup.procs documentationTejun Heo2017-07-171-3/+0
| | | | | | | | | 576dd464505f ("cgroup: drop the matching uid requirement on migration for cgroup v2") dropped the uid match requirement from "cgroup.procs" perm check but forgot to update the matching entry in the documentation. Update it. Signed-off-by: Tejun Heo <tj@kernel.org>
* cgroup-v2.txt: standardize document formatMauro Carvalho Chehab2017-07-141-221/+239
| | | | | | | | | | | | | | | | | | | Each text file under Documentation follows a different format. Some doesn't even have titles! Change its representation to follow the adopted standard, using ReST markups for it to be parseable by Sphinx: - Comment the internal index; - Use :Date: and :Author: for authorship; - Mark titles; - Mark literal blocks; - Adjust witespaces; - Mark notes; - Use table notation for the existing tables. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* mm/oom_kill: count global and memory cgroup oom killsKonstantin Khlebnikov2017-07-071-4/+16
| | | | | | | | | | | | | | | | | | | | | | | | Show count of oom killer invocations in /proc/vmstat and count of processes killed in memory cgroup in knob "memory.events" (in memory.oom_control for v1 cgroup). Also describe difference between "oom" and "oom_kill" in memory cgroup documentation. Currently oom in memory cgroup kills tasks iff shortage has happened inside page fault. These counters helps in monitoring oom kills - for now the only way is grepping for magic words in kernel log. [akpm@linux-foundation.org: fix for mem_cgroup_count_vm_event() rename] [akpm@linux-foundation.org: fix comment, per Konstantin] Link: http://lkml.kernel.org/r/149570810989.203600.9492483715840752937.stgit@buzz Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Roman Guschin <guroan@gmail.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: per-cgroup memory reclaim statsRoman Gushchin2017-07-071-0/+28
| | | | | | | | | | | | | | | | | | | | | | | | | Track the following reclaim counters for every memory cgroup: PGREFILL, PGSCAN, PGSTEAL, PGACTIVATE, PGDEACTIVATE, PGLAZYFREE and PGLAZYFREED. These values are exposed using the memory.stats interface of cgroup v2. The meaning of each value is the same as for global counters, available using /proc/vmstat. Also, for consistency, rename mem_cgroup_count_vm_event() to count_memcg_event_mm(). Link: http://lkml.kernel.org/r/1494530183-30808-1-git-send-email-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: implement "nsdelegate" mount optionTejun Heo2017-06-281-18/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, cgroup only supports delegation to !root users and cgroup namespaces don't get any special treatments. This limits the usefulness of cgroup namespaces as they by themselves can't be safe delegation boundaries. A process inside a cgroup can change the resource control knobs of the parent in the namespace root and may move processes in and out of the namespace if cgroups outside its namespace are visible somehow. This patch adds a new mount option "nsdelegate" which makes cgroup namespaces delegation boundaries. If set, cgroup behaves as if write permission based delegation took place at namespace boundaries - writes to the resource control knobs from the namespace root are denied and migration crossing the namespace boundary aren't allowed from inside the namespace. This allows cgroup namespace to function as a delegation boundary by itself. v2: Silently ignore nsdelegate specified on !init mounts. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Aravind Anbudurai <aru7@fb.com> Cc: Serge Hallyn <serge@hallyn.com> Cc: Eric Biederman <ebiederm@xmission.com>
* cgroup: "cgroup.subtree_control" should be writeable by delegateeTejun Heo2017-06-251-4/+5
| | | | | | | | | | | "cgroup.subtree_control" determines which resource types a cgroup wants to control. Unlike actual resource knobs, this is an attribute which belongs to the cgroup itself instead of its parent and thus should be writeable by the delegatee in a delegated cgroup. Update delegation documentation accordingly. Signed-off-by: Tejun Heo <tj@kernel.org>
* mm, docs: update memory.stat description with workingset* entriesRoman Gushchin2017-05-131-0/+12
| | | | | | | | | | | | | | | | | | | | | | Commit 4b4cea91691d ("mm: vmscan: fix IO/refault regression in cache workingset transition") introduced three new entries in memory stat file: - workingset_refault - workingset_activate - workingset_nodereclaim This commit adds a corresponding description to the cgroup v2 docs. Link: http://lkml.kernel.org/r/1494530293-31236-1-git-send-email-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memcontrol: provide shmem statisticsJohannes Weiner2017-05-041-0/+5
| | | | | | | | | | | | | | | | Cgroups currently don't report how much shmem they use, which can be useful data to have, in particular since shmem is included in the cache/file item while being reclaimed like anonymous memory. Add a counter to track shmem pages during charging and uncharging. Link: http://lkml.kernel.org/r/20170221164343.32252-1-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Chris Down <cdown@fb.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: Fix indenting in PID controller documentationTobias Klauser2017-03-061-5/+6
| | | | | | | | Follow the common documentation style in the file and indent the interface file description by a tab instead of just a space. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Tejun Heo <tj@kernel.org>
* Merge branch 'cgroup/for-4.11-rdmacg' into cgroup/for-4.11Tejun Heo2017-02-021-4/+42
|\ | | | | | | | | | | | | Merge in to resolve conflicts in Documentation/cgroup-v2.txt. The conflicts are from multiple section additions and trivial to resolve. Signed-off-by: Tejun Heo <tj@kernel.org>
| * rdmacg: Added documentation for rdmacgParav Pandit2017-01-101-0/+38
| | | | | | | | | | | | | | | | Added documentation for v1 and v2 version describing high level design and usage examples on using rdma controller. Signed-off-by: Parav Pandit <pandit.parav@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | cgroup: drop the matching uid requirement on migration for cgroup v2Tejun Heo2017-02-021-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Along with the write access to the cgroup.procs or tasks file, cgroup has required the writer's euid, unless root, to match [s]uid of the target process or task. On cgroup v1, this is necessary because there's nothing preventing a delegatee from pulling in tasks or processes from all over the system. If a user has a cgroup subdirectory delegated to it, the user would have write access to the cgroup.procs or tasks file. If there are no further checks than file write access check, the user would be able to pull processes from all over the system into its subhierarchy which is clearly not the intended behavior. The matching [s]uid requirement partially prevents this problem by allowing a delegatee to pull in the processes that belongs to it. This isn't a sufficient protection however, because a user would still be able to jump processes across two disjoint sub-hierarchies that has been delegated to them. cgroup v2 resolves the issue by requiring the writer to have access to the common ancestor of the cgroup.procs file of the source and target cgroups. This confines each delegatee to their own sub-hierarchy proper and bases all permission decisions on the cgroup filesystem rather than having to pull in explicit uid matching. cgroup v2 has still been applying the matching [s]uid requirement just for historical reasons. On cgroup2, the requirement doesn't serve any purpose while unnecessarily complicating the permission model. Let's drop it. Signed-off-by: Tejun Heo <tj@kernel.org>
* | cgroup, perf_event: make perf_event controller work on cgroup2 hierarchyTejun Heo2017-02-021-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | perf_event is a utility controller whose primary role is identifying cgroup membership to filter perf events; however, because it also tracks some per-css state, it can't be replaced by pure cgroup membership test. Mark the controller as implicitly enabled on the default hierarchy so that perf events can always be filtered based on cgroup v2 path as long as the controller is not mounted on a legacy hierarchy. "perf record" is updated accordingly so that it searches for both v1 and v2 hierarchies. A v1 hierarchy is used if perf_event is mounted on it; otherwise, it uses the v2 hierarchy. v2: Doc updated to reflect more flexible rebinding behavior. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
* | cgroup: Add missing cgroup-v2 PID controller documentation.Hans Ragas2017-01-101-0/+41
|/ | | | | Signed-off-by: Hans Ragas <hansr@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* Merge branch 'for-4.6-ns' of ↵Linus Torvalds2016-03-211-0/+147
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup namespace support from Tejun Heo: "These are changes to implement namespace support for cgroup which has been pending for quite some time now. It is very straight-forward and only affects what part of cgroup hierarchies are visible. After unsharing, mounting a cgroup fs will be scoped to the cgroups the task belonged to at the time of unsharing and the cgroup paths exposed to userland would be adjusted accordingly" * 'for-4.6-ns' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix and restructure error handling in copy_cgroup_ns() cgroup: fix alloc_cgroup_ns() error handling in copy_cgroup_ns() Add FS_USERNS_FLAG to cgroup fs cgroup: Add documentation for cgroup namespaces cgroup: mount cgroupns-root when inside non-init cgroupns kernfs: define kernfs_node_dentry cgroup: cgroup namespace setns support cgroup: introduce cgroup namespaces sched: new clone flag CLONE_NEWCGROUP for cgroup namespace kernfs: Add API to generate relative kernfs path
| * cgroup: Add documentation for cgroup namespacesSerge Hallyn2016-02-161-0/+147
| | | | | | | | | | | | Signed-off-by: Aditya Kali <adityakali@google.com> Signed-off-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Tejun Heo <tj@kernel.org>
* | Merge branch 'for-4.6' of ↵Linus Torvalds2016-03-191-1/+7
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "cgroup changes for v4.6-rc1. No userland visible behavior changes in this pull request. I'll send out a separate pull request for the addition of cgroup namespace support. - The biggest change is the revamping of cgroup core task migration and controller handling logic. There are quite a few places where controllers and tasks are manipulated. Previously, many of those places implemented custom operations for each specific use case assuming specific starting conditions. While this worked, it makes the code fragile and difficult to follow. The bulk of this pull request restructures these operations so that most related operations are performed through common helpers which implement recursive (subtrees are always processed consistently) and idempotent (they make cgroup hierarchy converge to the target state rather than performing operations assuming specific starting conditions). This makes the code a lot easier to understand, verify and extend. - Implicit controller support is added. This is primarily for using perf_event on the v2 hierarchy so that perf can match cgroup v2 path without requiring the user to do anything special. The kernel portion of perf_event changes is acked but userland changes are still pending review. - cgroup_no_v1= boot parameter added to ease testing cgroup v2 in certain environments. - There is a regression introduced during v4.4 devel cycle where attempts to migrate zombie tasks can mess up internal object management. This was fixed earlier this week and included in this pull request w/ stable cc'd. - Misc non-critical fixes and improvements" * 'for-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (44 commits) cgroup: avoid false positive gcc-6 warning cgroup: ignore css_sets associated with dead cgroups during migration Documentation: cgroup v2: Trivial heading correction. cgroup: implement cgroup_subsys->implicit_on_dfl cgroup: use css_set->mg_dst_cgrp for the migration target cgroup cgroup: make cgroup[_taskset]_migrate() take cgroup_root instead of cgroup cgroup: move migration destination verification out of cgroup_migrate_prepare_dst() cgroup: fix incorrect destination cgroup in cgroup_update_dfl_csses() cgroup: Trivial correction to reflect controller. cgroup: remove stale item in cgroup-v1 document INDEX file. cgroup: update css iteration in cgroup_update_dfl_csses() cgroup: allocate 2x cgrp_cset_links when setting up a new root cgroup: make cgroup_calc_subtree_ss_mask() take @this_ss_mask cgroup: reimplement rebind_subsystems() using cgroup_apply_control() and friends cgroup: use cgroup_apply_enable_control() in cgroup creation path cgroup: combine cgroup_mutex locking and offline css draining cgroup: factor out cgroup_{apply|finalize}_control() from cgroup_subtree_control_write() cgroup: introduce cgroup_{save|propagate|restore}_control() cgroup: make cgroup_drain_offline() and cgroup_apply_control_{disable|enable}() recursive cgroup: factor out cgroup_apply_control_enable() from cgroup_subtree_control_write() ...
| * | Documentation: cgroup v2: Trivial heading correction.Parav Pandit2016-03-111-1/+1
| | | | | | | | | | | | | | | | | | | | | Corrected the heading to match with index. Signed-off-by: Parav Pandit <pandit.parav@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | cgroup: document cgroup_no_v1=Johannes Weiner2016-02-161-0/+6
| |/ | | | | | | | | | | | | | | Add cgroup_no_v1= to kernel-parameters.txt, and a small blurb to cgroup-v2.txt section about transitioning from cgroup to cgroup2. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* | mm: memcontrol: reclaim and OOM kill when shrinking memory.max below usageJohannes Weiner2016-03-171-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Setting the original memory.limit_in_bytes hardlimit is subject to a race condition when the desired value is below the current usage. The code tries a few times to first reclaim and then see if the usage has dropped to where we would like it to be, but there is no locking, and the workload is free to continue making new charges up to the old limit. Thus, attempting to shrink a workload relies on pure luck and hope that the workload happens to cooperate. To fix this in the cgroup2 memory.max knob, do it the other way round: set the limit first, then try enforcement. And if reclaim is not able to succeed, trigger OOM kills in the group. Keep going until the new limit is met, we run out of OOM victims and there's only unreclaimable memory left, or the task writing to memory.max is killed. This allows users to shrink groups reliably, and the behavior is consistent with what happens when new charges are attempted in excess of memory.max. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: report kernel stack usage in cgroup2 memory.statVladimir Davydov2016-03-171-0/+4
| | | | | | | | | | | | | | | | | | | | Show how much memory is allocated to kernel stacks. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcontrol: report slab usage in cgroup2 memory.statVladimir Davydov2016-03-171-0/+15
| | | | | | | | | | | | | | | | | | | | | | Show how much memory is used for storing reclaimable and unreclaimable in-kernel data structures allocated from slab caches. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-4.5-fixes' of ↵Linus Torvalds2016-02-101-1/+1
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: - The destruction path of cgroup objects are asynchronous and multi-staged and some of them ended up destroying parents before children leading to failures in cpu and memory controllers. Ensure that parents are always destroyed after children. - cpuset mm node migration was performed synchronously while holding threadgroup and cgroup mutexes and the recent threadgroup locking update resulted in a possible deadlock. The migration is best effort and shouldn't have been performed under those locks to begin with. Made asynchronous. - Minor documentation fix. * 'for-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: Documentation: cgroup: Fix 'cgroup-legacy' -> 'cgroup-v1' cgroup: make sure a parent css isn't freed before its children cgroup: make sure a parent css isn't offlined before its children cpuset: make mm migration asynchronous
| * Documentation: cgroup: Fix 'cgroup-legacy' -> 'cgroup-v1'W. Trevor King2016-01-291-1/+1
| | | | | | | | | | | | | | | | This should have happened in 6255c46f (cgroup: rename cgroup documentations, 2016-01-11). Signed-off-by: W. Trevor King <wking@tremily.us> Signed-off-by: Tejun Heo <tj@kernel.org>
* | Documentation: cgroup-v2: add memory.stat::sock descriptionJohannes Weiner2016-02-031-0/+4
|/ | | | | | | | Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: memcontrol: basic memory statistics in cgroup2 memory controllerJohannes Weiner2016-01-211-0/+56
| | | | | | | | | | | | Provide a cgroup2 memory.stat that provides statistics on LRU memory and fault event counters. More consumers and breakdowns will follow. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Documentation: cgroup: add memory.swap.{current,max} descriptionVladimir Davydov2016-01-211-0/+33
| | | | | | | | | | The rationale of separate swap counter is given by Johannes Weiner. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cgroup: rename cgroup documentationsTejun Heo2016-01-121-0/+1293
cgroup-legacy may be too loaded. Rename the docs so that they're postfixed with v1 and v2. * s/cgroup-legacy/cgroup-v1/ * s/cgroup.txt/cgroup-v2.txt/ Signed-off-by: Tejun Heo <tj@kernel.org>