diff options
| -rw-r--r-- | kernel/cgroup_freezer.c | 38 |
1 files changed, 15 insertions, 23 deletions
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index c287627bed3..e7bebb7c6c3 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -153,13 +153,6 @@ static void freezer_destroy(struct cgroup_subsys *ss, kfree(cgroup_freezer(cgroup)); } -/* Task is frozen or will freeze immediately when next it gets woken */ -static bool is_task_frozen_enough(struct task_struct *task) -{ - return frozen(task) || - (task_is_stopped_or_traced(task) && freezing(task)); -} - /* * The call to cgroup_lock() in the freezer.state write method prevents * a write to that file racing against an attach, and hence the @@ -236,31 +229,30 @@ static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task) /* * caller must hold freezer->lock */ -static void update_freezer_state(struct cgroup *cgroup, +static void update_if_frozen(struct cgroup *cgroup, struct freezer *freezer) { struct cgroup_iter it; struct task_struct *task; unsigned int nfrozen = 0, ntotal = 0; + enum freezer_state old_state = freezer->state; cgroup_iter_start(cgroup, &it); while ((task = cgroup_iter_next(cgroup, &it))) { ntotal++; - if (is_task_frozen_enough(task)) + if (frozen(task)) nfrozen++; } - /* - * Transition to FROZEN when no new tasks can be added ensures - * that we never exist in the FROZEN state while there are unfrozen - * tasks. - */ - if (nfrozen == ntotal) - freezer->state = CGROUP_FROZEN; - else if (nfrozen > 0) - freezer->state = CGROUP_FREEZING; - else - freezer->state = CGROUP_THAWED; + if (old_state == CGROUP_THAWED) { + BUG_ON(nfrozen > 0); + } else if (old_state == CGROUP_FREEZING) { + if (nfrozen == ntotal) + freezer->state = CGROUP_FROZEN; + } else { /* old_state == CGROUP_FROZEN */ + BUG_ON(nfrozen != ntotal); + } + cgroup_iter_end(cgroup, &it); } @@ -279,7 +271,7 @@ static int freezer_read(struct cgroup *cgroup, struct cftype *cft, if (state == CGROUP_FREEZING) { /* We change from FREEZING to FROZEN lazily if the cgroup was * only partially frozen when we exitted write. */ - update_freezer_state(cgroup, freezer); + update_if_frozen(cgroup, freezer); state = freezer->state; } spin_unlock_irq(&freezer->lock); @@ -301,7 +293,7 @@ static int try_to_freeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) while ((task = cgroup_iter_next(cgroup, &it))) { if (!freeze_task(task, true)) continue; - if (is_task_frozen_enough(task)) + if (frozen(task)) continue; if (!freezing(task) && !freezer_should_skip(task)) num_cant_freeze_now++; @@ -335,7 +327,7 @@ static int freezer_change_state(struct cgroup *cgroup, spin_lock_irq(&freezer->lock); - update_freezer_state(cgroup, freezer); + update_if_frozen(cgroup, freezer); if (goal_state == freezer->state) goto out; |