diff options
Diffstat (limited to 'kernel/freezer.c')
| -rw-r--r-- | kernel/freezer.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/kernel/freezer.c b/kernel/freezer.c index 11f82a4d4ea..aa6a8aadb91 100644 --- a/kernel/freezer.c +++ b/kernel/freezer.c @@ -19,6 +19,12 @@ EXPORT_SYMBOL(system_freezing_cnt); bool pm_freezing; bool pm_nosig_freezing; +/* + * Temporary export for the deadlock workaround in ata_scsi_hotplug(). + * Remove once the hack becomes unnecessary. + */ +EXPORT_SYMBOL_GPL(pm_freezing); + /* protects freezing and frozen transitions */ static DEFINE_SPINLOCK(freezer_lock); @@ -33,7 +39,7 @@ static DEFINE_SPINLOCK(freezer_lock); */ bool freezing_slow_path(struct task_struct *p) { - if (p->flags & PF_NOFREEZE) + if (p->flags & (PF_NOFREEZE | PF_SUSPEND_TASK)) return false; if (pm_nosig_freezing || cgroup_freezing(p)) @@ -110,23 +116,28 @@ bool freeze_task(struct task_struct *p) { unsigned long flags; + /* + * This check can race with freezer_do_not_count, but worst case that + * will result in an extra wakeup being sent to the task. It does not + * race with freezer_count(), the barriers in freezer_count() and + * freezer_should_skip() ensure that either freezer_count() sees + * freezing == true in try_to_freeze() and freezes, or + * freezer_should_skip() sees !PF_FREEZE_SKIP and freezes the task + * normally. + */ + if (freezer_should_skip(p)) + return false; + spin_lock_irqsave(&freezer_lock, flags); if (!freezing(p) || frozen(p)) { spin_unlock_irqrestore(&freezer_lock, flags); return false; } - if (!(p->flags & PF_KTHREAD)) { + if (!(p->flags & PF_KTHREAD)) fake_signal_wake_up(p); - /* - * fake_signal_wake_up() goes through p's scheduler - * lock and guarantees that TASK_STOPPED/TRACED -> - * TASK_RUNNING transition can't race with task state - * testing in try_to_freeze_tasks(). - */ - } else { + else wake_up_state(p, TASK_INTERRUPTIBLE); - } spin_unlock_irqrestore(&freezer_lock, flags); return true; |