diff options
| -rw-r--r-- | include/linux/cgroup-defs.h | 1 | ||||
| -rw-r--r-- | include/linux/cgroup.h | 1 | ||||
| -rw-r--r-- | kernel/cgroup/cgroup.c | 44 |
3 files changed, 39 insertions, 7 deletions
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index 77258d276f93..1615b9c17e02 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -216,6 +216,7 @@ struct css_set { */ struct list_head tasks; struct list_head mg_tasks; + struct list_head dying_tasks; /* all css_task_iters currently walking this cset */ struct list_head task_iters; diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 05ed2a209e74..0297f930a56e 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -60,6 +60,7 @@ struct css_task_iter { struct list_head *task_pos; struct list_head *tasks_head; struct list_head *mg_tasks_head; + struct list_head *dying_tasks_head; struct css_set *cur_cset; struct css_set *cur_dcset; diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 035aee466bbf..a7df319c2e9a 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -739,6 +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), @@ -1213,6 +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); @@ -4399,15 +4401,18 @@ 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 @@ -4446,6 +4451,8 @@ static void css_task_iter_skip(struct css_task_iter *it, static void css_task_iter_advance(struct css_task_iter *it) { + struct task_struct *task; + lockdep_assert_held(&css_set_lock); repeat: if (it->task_pos) { @@ -4462,17 +4469,32 @@ repeat: 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 { /* 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; + } } /** @@ -6009,6 +6031,7 @@ 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)); @@ -6034,6 +6057,13 @@ 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) |