diff options
Diffstat (limited to 'kernel/cgroup')
| -rw-r--r-- | kernel/cgroup/cgroup-v1.c | 1 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup.c | 122 | ||||
| -rw-r--r-- | kernel/cgroup/cpuset.c | 15 | ||||
| -rw-r--r-- | kernel/cgroup/pids.c | 5 | ||||
| -rw-r--r-- | kernel/cgroup/rdma.c | 5 | ||||
| -rw-r--r-- | kernel/cgroup/rstat.c | 1 |
6 files changed, 108 insertions, 41 deletions
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index 68ca5de7ec27..88006be40ea3 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only #include "cgroup-internal.h" #include <linux/ctype.h> diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 217cec4e22c6..bf9dbffd46b1 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -215,7 +215,8 @@ static struct cftype cgroup_base_files[]; static int cgroup_apply_control(struct cgroup *cgrp); static void cgroup_finalize_control(struct cgroup *cgrp, int ret); -static void css_task_iter_advance(struct css_task_iter *it); +static void css_task_iter_skip(struct css_task_iter *it, + struct task_struct *task); static int cgroup_destroy_locked(struct cgroup *cgrp); static struct cgroup_subsys_state *css_create(struct cgroup *cgrp, struct cgroup_subsys *ss); @@ -738,6 +739,7 @@ struct css_set init_css_set = { .dom_cset = &init_css_set, .tasks = LIST_HEAD_INIT(init_css_set.tasks), .mg_tasks = LIST_HEAD_INIT(init_css_set.mg_tasks), + .dying_tasks = LIST_HEAD_INIT(init_css_set.dying_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), @@ -843,6 +845,21 @@ static void css_set_update_populated(struct css_set *cset, bool populated) cgroup_update_populated(link->cgrp, populated); } +/* + * @task is leaving, advance task iterators which are pointing to it so + * that they can resume at the next position. Advancing an iterator might + * remove it from the list, use safe walk. See css_task_iter_skip() for + * details. + */ +static void css_set_skip_task_iters(struct css_set *cset, + struct task_struct *task) +{ + struct css_task_iter *it, *pos; + + list_for_each_entry_safe(it, pos, &cset->task_iters, iters_node) + css_task_iter_skip(it, task); +} + /** * css_set_move_task - move a task from one css_set to another * @task: task being moved @@ -868,22 +885,9 @@ static void css_set_move_task(struct task_struct *task, css_set_update_populated(to_cset, true); if (from_cset) { - struct css_task_iter *it, *pos; - WARN_ON_ONCE(list_empty(&task->cg_list)); - /* - * @task is leaving, advance task iterators which are - * pointing to it so that they can resume at the next - * position. Advancing an iterator might remove it from - * the list, use safe walk. See css_task_iter_advance*() - * for details. - */ - list_for_each_entry_safe(it, pos, &from_cset->task_iters, - iters_node) - if (it->task_pos == &task->cg_list) - css_task_iter_advance(it); - + css_set_skip_task_iters(from_cset, task); list_del_init(&task->cg_list); if (!css_set_populated(from_cset)) css_set_update_populated(from_cset, false); @@ -1210,6 +1214,7 @@ static struct css_set *find_css_set(struct css_set *old_cset, cset->dom_cset = cset; INIT_LIST_HEAD(&cset->tasks); INIT_LIST_HEAD(&cset->mg_tasks); + INIT_LIST_HEAD(&cset->dying_tasks); INIT_LIST_HEAD(&cset->task_iters); INIT_LIST_HEAD(&cset->threaded_csets); INIT_HLIST_NODE(&cset->hlist); @@ -1810,11 +1815,13 @@ int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node, enum cgroup2_param { Opt_nsdelegate, + Opt_memory_localevents, nr__cgroup2_params }; static const struct fs_parameter_spec cgroup2_param_specs[] = { - fsparam_flag ("nsdelegate", Opt_nsdelegate), + fsparam_flag("nsdelegate", Opt_nsdelegate), + fsparam_flag("memory_localevents", Opt_memory_localevents), {} }; @@ -1837,6 +1844,9 @@ static int cgroup2_parse_param(struct fs_context *fc, struct fs_parameter *param case Opt_nsdelegate: ctx->flags |= CGRP_ROOT_NS_DELEGATE; return 0; + case Opt_memory_localevents: + ctx->flags |= CGRP_ROOT_MEMORY_LOCAL_EVENTS; + return 0; } return -EINVAL; } @@ -1848,6 +1858,11 @@ static void apply_cgroup_root_flags(unsigned int root_flags) cgrp_dfl_root.flags |= CGRP_ROOT_NS_DELEGATE; else cgrp_dfl_root.flags &= ~CGRP_ROOT_NS_DELEGATE; + + if (root_flags & CGRP_ROOT_MEMORY_LOCAL_EVENTS) + cgrp_dfl_root.flags |= CGRP_ROOT_MEMORY_LOCAL_EVENTS; + else + cgrp_dfl_root.flags &= ~CGRP_ROOT_MEMORY_LOCAL_EVENTS; } } @@ -1855,6 +1870,8 @@ static int cgroup_show_options(struct seq_file *seq, struct kernfs_root *kf_root { if (cgrp_dfl_root.flags & CGRP_ROOT_NS_DELEGATE) seq_puts(seq, ",nsdelegate"); + if (cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_LOCAL_EVENTS) + seq_puts(seq, ",memory_localevents"); return 0; } @@ -4396,15 +4413,18 @@ static void css_task_iter_advance_css_set(struct css_task_iter *it) it->task_pos = NULL; return; } - } while (!css_set_populated(cset)); + } while (!css_set_populated(cset) && list_empty(&cset->dying_tasks)); if (!list_empty(&cset->tasks)) it->task_pos = cset->tasks.next; - else + else if (!list_empty(&cset->mg_tasks)) it->task_pos = cset->mg_tasks.next; + else + it->task_pos = cset->dying_tasks.next; it->tasks_head = &cset->tasks; it->mg_tasks_head = &cset->mg_tasks; + it->dying_tasks_head = &cset->dying_tasks; /* * We don't keep css_sets locked across iteration steps and thus @@ -4430,9 +4450,20 @@ static void css_task_iter_advance_css_set(struct css_task_iter *it) list_add(&it->iters_node, &cset->task_iters); } +static void css_task_iter_skip(struct css_task_iter *it, + struct task_struct *task) +{ + lockdep_assert_held(&css_set_lock); + + if (it->task_pos == &task->cg_list) { + it->task_pos = it->task_pos->next; + it->flags |= CSS_TASK_ITER_SKIPPED; + } +} + static void css_task_iter_advance(struct css_task_iter *it) { - struct list_head *next; + struct task_struct *task; lockdep_assert_held(&css_set_lock); repeat: @@ -4442,25 +4473,40 @@ repeat: * consumed first and then ->mg_tasks. After ->mg_tasks, * we move onto the next cset. */ - next = it->task_pos->next; - - if (next == it->tasks_head) - next = it->mg_tasks_head->next; + if (it->flags & CSS_TASK_ITER_SKIPPED) + it->flags &= ~CSS_TASK_ITER_SKIPPED; + else + it->task_pos = it->task_pos->next; - if (next == it->mg_tasks_head) + if (it->task_pos == it->tasks_head) + it->task_pos = it->mg_tasks_head->next; + if (it->task_pos == it->mg_tasks_head) + it->task_pos = it->dying_tasks_head->next; + if (it->task_pos == it->dying_tasks_head) css_task_iter_advance_css_set(it); - else - it->task_pos = next; } else { /* called from start, proceed to the first cset */ css_task_iter_advance_css_set(it); } - /* if PROCS, skip over tasks which aren't group leaders */ - if ((it->flags & CSS_TASK_ITER_PROCS) && it->task_pos && - !thread_group_leader(list_entry(it->task_pos, struct task_struct, - cg_list))) - goto repeat; + if (!it->task_pos) + return; + + task = list_entry(it->task_pos, struct task_struct, cg_list); + + if (it->flags & CSS_TASK_ITER_PROCS) { + /* if PROCS, skip over tasks which aren't group leaders */ + if (!thread_group_leader(task)) + goto repeat; + + /* and dying leaders w/o live member threads */ + if (!atomic_read(&task->signal->live)) + goto repeat; + } else { + /* skip all dying ones */ + if (task->flags & PF_EXITING) + goto repeat; + } } /** @@ -4516,6 +4562,10 @@ struct task_struct *css_task_iter_next(struct css_task_iter *it) spin_lock_irq(&css_set_lock); + /* @it may be half-advanced by skips, finish advancing */ + if (it->flags & CSS_TASK_ITER_SKIPPED) + css_task_iter_advance(it); + if (it->task_pos) { it->cur_task = list_entry(it->task_pos, struct task_struct, cg_list); @@ -5997,6 +6047,7 @@ void cgroup_exit(struct task_struct *tsk) if (!list_empty(&tsk->cg_list)) { spin_lock_irq(&css_set_lock); css_set_move_task(tsk, cset, NULL, false); + list_add_tail(&tsk->cg_list, &cset->dying_tasks); cset->nr_tasks--; WARN_ON_ONCE(cgroup_task_frozen(tsk)); @@ -6022,6 +6073,13 @@ void cgroup_release(struct task_struct *task) do_each_subsys_mask(ss, ssid, have_release_callback) { ss->release(task); } while_each_subsys_mask(); + + if (use_task_css_set_links) { + spin_lock_irq(&css_set_lock); + css_set_skip_task_iters(task_css_set(task), task); + list_del_init(&task->cg_list); + spin_unlock_irq(&css_set_lock); + } } void cgroup_free(struct task_struct *task) @@ -6325,7 +6383,7 @@ static struct kobj_attribute cgroup_delegate_attr = __ATTR_RO(delegate); static ssize_t features_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { - return snprintf(buf, PAGE_SIZE, "nsdelegate\n"); + return snprintf(buf, PAGE_SIZE, "nsdelegate\nmemory_localevents\n"); } static struct kobj_attribute cgroup_features_attr = __ATTR_RO(features); diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 6a1942ed781c..515525ff1cfd 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -3254,10 +3254,23 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask) spin_unlock_irqrestore(&callback_lock, flags); } +/** + * cpuset_cpus_allowed_fallback - final fallback before complete catastrophe. + * @tsk: pointer to task_struct with which the scheduler is struggling + * + * Description: In the case that the scheduler cannot find an allowed cpu in + * tsk->cpus_allowed, we fall back to task_cs(tsk)->cpus_allowed. In legacy + * mode however, this value is the same as task_cs(tsk)->effective_cpus, + * which will not contain a sane cpumask during cases such as cpu hotplugging. + * This is the absolute last resort for the scheduler and it is only used if + * _every_ other avenue has been traveled. + **/ + void cpuset_cpus_allowed_fallback(struct task_struct *tsk) { rcu_read_lock(); - do_set_cpus_allowed(tsk, task_cs(tsk)->effective_cpus); + do_set_cpus_allowed(tsk, is_in_v2_mode() ? + task_cs(tsk)->cpus_allowed : cpu_possible_mask); rcu_read_unlock(); /* diff --git a/kernel/cgroup/pids.c b/kernel/cgroup/pids.c index c9960baaa14f..8e513a573fe9 100644 --- a/kernel/cgroup/pids.c +++ b/kernel/cgroup/pids.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Process number limiting controller for cgroups. * @@ -25,10 +26,6 @@ * a superset of parent/child/pids.current. * * Copyright (C) 2015 Aleksa Sarai <cyphar@cyphar.com> - * - * This file is subject to the terms and conditions of version 2 of the GNU - * General Public License. See the file COPYING in the main directory of the - * Linux distribution for more details. */ #include <linux/kernel.h> diff --git a/kernel/cgroup/rdma.c b/kernel/cgroup/rdma.c index 1d75ae7f1cb7..ae042c347c64 100644 --- a/kernel/cgroup/rdma.c +++ b/kernel/cgroup/rdma.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * RDMA resource limiting controller for cgroups. * @@ -5,10 +6,6 @@ * additional RDMA resources after a certain limit is reached. * * Copyright (C) 2016 Parav Pandit <pandit.parav@gmail.com> - * - * This file is subject to the terms and conditions of version 2 of the GNU - * General Public License. See the file COPYING in the main directory of the - * Linux distribution for more details. */ #include <linux/bitops.h> diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index bb95a35e8c2d..ca19b4c8acf5 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only #include "cgroup-internal.h" #include <linux/sched/cputime.h> |