diff options
Diffstat (limited to 'include/linux/sched.h')
| -rw-r--r-- | include/linux/sched.h | 106 |
1 files changed, 69 insertions, 37 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index a7b4a980eb2f..004e6d56a499 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -949,6 +949,10 @@ struct task_struct { struct srcu_ctr __percpu *trc_reader_scp; #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ +#ifdef CONFIG_TRIVIAL_PREEMPT_RCU + int rcu_trivial_preempt_nesting; +#endif /* #ifdef CONFIG_TRIVIAL_PREEMPT_RCU */ + struct sched_info sched_info; struct list_head tasks; @@ -1159,12 +1163,9 @@ struct task_struct { /* * executable name, excluding path. * - * - normally initialized begin_new_exec() - * - set it with set_task_comm() - * - strscpy_pad() to ensure it is always NUL-terminated and - * zero-padded - * - task_lock() to ensure the operation is atomic and the name is - * fully updated. + * - normally initialized by begin_new_exec() + * - set it with set_task_comm() to ensure it is always + * NUL-terminated and zero-padded */ char comm[TASK_COMM_LEN]; @@ -1238,6 +1239,7 @@ struct task_struct { #endif struct mutex *blocked_on; /* lock we're blocked on */ + raw_spinlock_t blocked_lock; #ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER /* @@ -2179,61 +2181,85 @@ extern int __cond_resched_rwlock_write(rwlock_t *lock) __must_hold(lock); }) #ifndef CONFIG_PREEMPT_RT + +/* + * With proxy exec, if a task has been proxy-migrated, it may be a donor + * on a cpu that it can't actually run on. Thus we need a special state + * to denote that the task is being woken, but that it needs to be + * evaluated for return-migration before it is run. So if the task is + * blocked_on PROXY_WAKING, return migrate it before running it. + */ +#define PROXY_WAKING ((struct mutex *)(-1L)) + static inline struct mutex *__get_task_blocked_on(struct task_struct *p) { - struct mutex *m = p->blocked_on; - - if (m) - lockdep_assert_held_once(&m->wait_lock); - return m; + lockdep_assert_held_once(&p->blocked_lock); + return p->blocked_on == PROXY_WAKING ? NULL : p->blocked_on; } static inline void __set_task_blocked_on(struct task_struct *p, struct mutex *m) { - struct mutex *blocked_on = READ_ONCE(p->blocked_on); - WARN_ON_ONCE(!m); /* The task should only be setting itself as blocked */ WARN_ON_ONCE(p != current); - /* Currently we serialize blocked_on under the mutex::wait_lock */ - lockdep_assert_held_once(&m->wait_lock); + /* Currently we serialize blocked_on under the task::blocked_lock */ + lockdep_assert_held_once(&p->blocked_lock); /* * Check ensure we don't overwrite existing mutex value * with a different mutex. Note, setting it to the same * lock repeatedly is ok. */ - WARN_ON_ONCE(blocked_on && blocked_on != m); - WRITE_ONCE(p->blocked_on, m); + WARN_ON_ONCE(p->blocked_on && p->blocked_on != m); + p->blocked_on = m; } -static inline void set_task_blocked_on(struct task_struct *p, struct mutex *m) +static inline void __clear_task_blocked_on(struct task_struct *p, struct mutex *m) { - guard(raw_spinlock_irqsave)(&m->wait_lock); - __set_task_blocked_on(p, m); + /* Currently we serialize blocked_on under the task::blocked_lock */ + lockdep_assert_held_once(&p->blocked_lock); + /* + * There may be cases where we re-clear already cleared + * blocked_on relationships, but make sure we are not + * clearing the relationship with a different lock. + */ + WARN_ON_ONCE(m && p->blocked_on && p->blocked_on != m && p->blocked_on != PROXY_WAKING); + p->blocked_on = NULL; } -static inline void __clear_task_blocked_on(struct task_struct *p, struct mutex *m) +static inline void clear_task_blocked_on(struct task_struct *p, struct mutex *m) { - if (m) { - struct mutex *blocked_on = READ_ONCE(p->blocked_on); + guard(raw_spinlock_irqsave)(&p->blocked_lock); + __clear_task_blocked_on(p, m); +} - /* Currently we serialize blocked_on under the mutex::wait_lock */ - lockdep_assert_held_once(&m->wait_lock); - /* - * There may be cases where we re-clear already cleared - * blocked_on relationships, but make sure we are not - * clearing the relationship with a different lock. - */ - WARN_ON_ONCE(blocked_on && blocked_on != m); +static inline void __set_task_blocked_on_waking(struct task_struct *p, struct mutex *m) +{ + /* Currently we serialize blocked_on under the task::blocked_lock */ + lockdep_assert_held_once(&p->blocked_lock); + + if (!sched_proxy_exec()) { + __clear_task_blocked_on(p, m); + return; } - WRITE_ONCE(p->blocked_on, NULL); + + /* Don't set PROXY_WAKING if blocked_on was already cleared */ + if (!p->blocked_on) + return; + /* + * There may be cases where we set PROXY_WAKING on tasks that were + * already set to waking, but make sure we are not changing + * the relationship with a different lock. + */ + WARN_ON_ONCE(m && p->blocked_on != m && p->blocked_on != PROXY_WAKING); + p->blocked_on = PROXY_WAKING; } -static inline void clear_task_blocked_on(struct task_struct *p, struct mutex *m) +static inline void set_task_blocked_on_waking(struct task_struct *p, struct mutex *m) { - guard(raw_spinlock_irqsave)(&m->wait_lock); - __clear_task_blocked_on(p, m); + guard(raw_spinlock_irqsave)(&p->blocked_lock); + __set_task_blocked_on_waking(p, m); } + #else static inline void __clear_task_blocked_on(struct task_struct *p, struct rt_mutex *m) { @@ -2242,6 +2268,14 @@ static inline void __clear_task_blocked_on(struct task_struct *p, struct rt_mute static inline void clear_task_blocked_on(struct task_struct *p, struct rt_mutex *m) { } + +static inline void __set_task_blocked_on_waking(struct task_struct *p, struct rt_mutex *m) +{ +} + +static inline void set_task_blocked_on_waking(struct task_struct *p, struct rt_mutex *m) +{ +} #endif /* !CONFIG_PREEMPT_RT */ static __always_inline bool need_resched(void) @@ -2354,7 +2388,6 @@ static __always_inline void alloc_tag_restore(struct alloc_tag *tag, struct allo #ifdef CONFIG_SCHED_MM_CID void sched_mm_cid_before_execve(struct task_struct *t); void sched_mm_cid_after_execve(struct task_struct *t); -void sched_mm_cid_fork(struct task_struct *t); void sched_mm_cid_exit(struct task_struct *t); static __always_inline int task_mm_cid(struct task_struct *t) { @@ -2363,7 +2396,6 @@ static __always_inline int task_mm_cid(struct task_struct *t) #else static inline void sched_mm_cid_before_execve(struct task_struct *t) { } static inline void sched_mm_cid_after_execve(struct task_struct *t) { } -static inline void sched_mm_cid_fork(struct task_struct *t) { } static inline void sched_mm_cid_exit(struct task_struct *t) { } static __always_inline int task_mm_cid(struct task_struct *t) { |