diff options
| -rw-r--r-- | include/linux/cgroup-defs.h | 33 | ||||
| -rw-r--r-- | include/linux/cgroup.h | 3 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup.c | 69 |
3 files changed, 97 insertions, 8 deletions
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index ae7bc1e70085..651c4363c85e 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -172,6 +172,14 @@ struct css_set { /* reference count */ refcount_t refcount; + /* + * For a domain cgroup, the following points to self. If threaded, + * to the matching cset of the nearest domain ancestor. The + * dom_cset provides access to the domain cgroup and its csses to + * which domain level resource consumptions should be charged. + */ + struct css_set *dom_cset; + /* the default cgroup associated with this css_set */ struct cgroup *dfl_cgrp; @@ -200,6 +208,10 @@ struct css_set { */ struct list_head e_cset_node[CGROUP_SUBSYS_COUNT]; + /* all threaded csets whose ->dom_cset points to this cset */ + struct list_head threaded_csets; + struct list_head threaded_csets_node; + /* * List running through all cgroup groups in the same hash * slot. Protected by css_set_lock @@ -267,12 +279,16 @@ struct cgroup { * doesn't have any tasks. * * All children which have non-zero nr_populated_csets and/or - * nr_populated_children of their own contribute one to - * nr_populated_children. The counter is zero iff this cgroup's - * subtree proper doesn't have any tasks. + * nr_populated_children of their own contribute one to either + * nr_populated_domain_children or nr_populated_threaded_children + * depending on their type. Each counter is zero iff all cgroups + * of the type in the subtree proper don't have any tasks. */ int nr_populated_csets; - int nr_populated_children; + int nr_populated_domain_children; + int nr_populated_threaded_children; + + int nr_threaded_children; /* # of live threaded child cgroups */ struct kernfs_node *kn; /* cgroup kernfs entry */ struct cgroup_file procs_file; /* handle for "cgroup.procs" */ @@ -311,6 +327,15 @@ struct cgroup { struct list_head e_csets[CGROUP_SUBSYS_COUNT]; /* + * If !threaded, self. If threaded, it points to the nearest + * domain ancestor. Inside a threaded subtree, cgroups are exempt + * from process granularity and no-internal-task constraint. + * Domain level resource consumptions which aren't tied to a + * specific task are charged to the dom_cgrp. + */ + struct cgroup *dom_cgrp; + + /* * list of pidlists, up to two for each namespace (one for procs, one * for tasks); created on demand. */ diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index cae5831ae650..b7dd23040cd5 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -541,7 +541,8 @@ static inline bool task_under_cgroup_hierarchy(struct task_struct *task, /* no synchronization, the result can only be used as a hint */ static inline bool cgroup_is_populated(struct cgroup *cgrp) { - return cgrp->nr_populated_csets + cgrp->nr_populated_children; + return cgrp->nr_populated_csets + cgrp->nr_populated_domain_children + + cgrp->nr_populated_threaded_children; } /* returns ino associated with a cgroup */ diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 3c5a37a9a892..c7e1c243b77d 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -330,6 +330,11 @@ static bool cgroup_has_tasks(struct cgroup *cgrp) return cgrp->nr_populated_csets; } +static bool cgroup_is_threaded(struct cgroup *cgrp) +{ + return cgrp->dom_cgrp != cgrp; +} + /* subsystems visibly enabled on a cgroup */ static u16 cgroup_control(struct cgroup *cgrp) { @@ -565,9 +570,11 @@ EXPORT_SYMBOL_GPL(of_css); */ struct css_set init_css_set = { .refcount = REFCOUNT_INIT(1), + .dom_cset = &init_css_set, .tasks = LIST_HEAD_INIT(init_css_set.tasks), .mg_tasks = LIST_HEAD_INIT(init_css_set.mg_tasks), .task_iters = LIST_HEAD_INIT(init_css_set.task_iters), + .threaded_csets = LIST_HEAD_INIT(init_css_set.threaded_csets), .cgrp_links = LIST_HEAD_INIT(init_css_set.cgrp_links), .mg_preload_node = LIST_HEAD_INIT(init_css_set.mg_preload_node), .mg_node = LIST_HEAD_INIT(init_css_set.mg_node), @@ -575,6 +582,11 @@ struct css_set init_css_set = { static int css_set_count = 1; /* 1 for init_css_set */ +static bool css_set_threaded(struct css_set *cset) +{ + return cset->dom_cset != cset; +} + /** * css_set_populated - does a css_set contain any tasks? * @cset: target css_set @@ -618,10 +630,14 @@ static void cgroup_update_populated(struct cgroup *cgrp, bool populated) do { bool was_populated = cgroup_is_populated(cgrp); - if (!child) + if (!child) { cgrp->nr_populated_csets += adj; - else - cgrp->nr_populated_children += adj; + } else { + if (cgroup_is_threaded(child)) + cgrp->nr_populated_threaded_children += adj; + else + cgrp->nr_populated_domain_children += adj; + } if (was_populated == cgroup_is_populated(cgrp)) break; @@ -747,6 +763,8 @@ void put_css_set_locked(struct css_set *cset) if (!refcount_dec_and_test(&cset->refcount)) return; + WARN_ON_ONCE(!list_empty(&cset->threaded_csets)); + /* This css_set is dead. unlink it and release cgroup and css refs */ for_each_subsys(ss, ssid) { list_del(&cset->e_cset_node[ssid]); @@ -763,6 +781,11 @@ void put_css_set_locked(struct css_set *cset) kfree(link); } + if (css_set_threaded(cset)) { + list_del(&cset->threaded_csets_node); + put_css_set_locked(cset->dom_cset); + } + kfree_rcu(cset, rcu_head); } @@ -781,6 +804,7 @@ static bool compare_css_sets(struct css_set *cset, struct cgroup *new_cgrp, struct cgroup_subsys_state *template[]) { + struct cgroup *new_dfl_cgrp; struct list_head *l1, *l2; /* @@ -791,6 +815,16 @@ static bool compare_css_sets(struct css_set *cset, if (memcmp(template, cset->subsys, sizeof(cset->subsys))) return false; + + /* @cset's domain should match the default cgroup's */ + if (cgroup_on_dfl(new_cgrp)) + new_dfl_cgrp = new_cgrp; + else + new_dfl_cgrp = old_cset->dfl_cgrp; + + if (new_dfl_cgrp->dom_cgrp != cset->dom_cset->dfl_cgrp) + return false; + /* * Compare cgroup pointers in order to distinguish between * different cgroups in hierarchies. As different cgroups may @@ -998,9 +1032,11 @@ static struct css_set *find_css_set(struct css_set *old_cset, } refcount_set(&cset->refcount, 1); + cset->dom_cset = cset; INIT_LIST_HEAD(&cset->tasks); INIT_LIST_HEAD(&cset->mg_tasks); INIT_LIST_HEAD(&cset->task_iters); + INIT_LIST_HEAD(&cset->threaded_csets); INIT_HLIST_NODE(&cset->hlist); INIT_LIST_HEAD(&cset->cgrp_links); INIT_LIST_HEAD(&cset->mg_preload_node); @@ -1038,6 +1074,28 @@ static struct css_set *find_css_set(struct css_set *old_cset, spin_unlock_irq(&css_set_lock); + /* + * If @cset should be threaded, look up the matching dom_cset and + * link them up. We first fully initialize @cset then look for the + * dom_cset. It's simpler this way and safe as @cset is guaranteed + * to stay empty until we return. + */ + if (cgroup_is_threaded(cset->dfl_cgrp)) { + struct css_set *dcset; + + dcset = find_css_set(cset, cset->dfl_cgrp->dom_cgrp); + if (!dcset) { + put_css_set(cset); + return NULL; + } + + spin_lock_irq(&css_set_lock); + cset->dom_cset = dcset; + list_add_tail(&cset->threaded_csets_node, + &dcset->threaded_csets); + spin_unlock_irq(&css_set_lock); + } + return cset; } @@ -1680,6 +1738,7 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp) mutex_init(&cgrp->pidlist_mutex); cgrp->self.cgroup = cgrp; cgrp->self.flags |= CSS_ONLINE; + cgrp->dom_cgrp = cgrp; for_each_subsys(ss, ssid) INIT_LIST_HEAD(&cgrp->e_csets[ssid]); @@ -4408,6 +4467,7 @@ static void kill_css(struct cgroup_subsys_state *css) static int cgroup_destroy_locked(struct cgroup *cgrp) __releases(&cgroup_mutex) __acquires(&cgroup_mutex) { + struct cgroup *parent = cgroup_parent(cgrp); struct cgroup_subsys_state *css; struct cgrp_cset_link *link; int ssid; @@ -4452,6 +4512,9 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) */ kernfs_remove(cgrp->kn); + if (parent && cgroup_is_threaded(cgrp)) + parent->nr_threaded_children--; + cgroup1_check_for_release(cgroup_parent(cgrp)); /* put the base reference */ |