diff options
Diffstat (limited to 'kernel/sched/core.c')
| -rw-r--r-- | kernel/sched/core.c | 23 |
1 files changed, 14 insertions, 9 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 49541e3c1295..5a50c4e41be9 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2242,8 +2242,8 @@ static __always_inline int task_state_match(struct task_struct *p, unsigned int state) { /* - * Serialize against current_save_and_set_rtlock_wait_state() and - * current_restore_rtlock_saved_state(). + * Serialize against current_save_and_set_rtlock_wait_state(), + * current_restore_rtlock_saved_state(), and __refrigerator(). */ guard(raw_spinlock_irq)(&p->pi_lock); return __task_state_match(p, state); @@ -4015,13 +4015,17 @@ static void ttwu_queue(struct task_struct *p, int cpu, int wake_flags) * The caller holds p::pi_lock if p != current or has preemption * disabled when p == current. * - * The rules of PREEMPT_RT saved_state: + * The rules of saved_state: * * The related locking code always holds p::pi_lock when updating * p::saved_state, which means the code is fully serialized in both cases. * - * The lock wait and lock wakeups happen via TASK_RTLOCK_WAIT. No other - * bits set. This allows to distinguish all wakeup scenarios. + * For PREEMPT_RT, the lock wait and lock wakeups happen via TASK_RTLOCK_WAIT. + * No other bits set. This allows to distinguish all wakeup scenarios. + * + * For FREEZER, the wakeup happens via TASK_FROZEN. No other bits set. This + * allows us to prevent early wakeup of tasks before they can be run on + * asymmetric ISA architectures (eg ARMv9). */ static __always_inline bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) @@ -4037,10 +4041,11 @@ bool ttwu_state_match(struct task_struct *p, unsigned int state, int *success) /* * Saved state preserves the task state across blocking on - * an RT lock. If the state matches, set p::saved_state to - * TASK_RUNNING, but do not wake the task because it waits - * for a lock wakeup. Also indicate success because from - * the regular waker's point of view this has succeeded. + * an RT lock or TASK_FREEZABLE tasks. If the state matches, + * set p::saved_state to TASK_RUNNING, but do not wake the task + * because it waits for a lock wakeup or __thaw_task(). Also + * indicate success because from the regular waker's point of + * view this has succeeded. * * After acquiring the lock the task will restore p::__state * from p::saved_state which ensures that the regular |