diff options
Diffstat (limited to 'include/linux/sched/task.h')
| -rw-r--r-- | include/linux/sched/task.h | 51 |
1 files changed, 25 insertions, 26 deletions
diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index a23af225c898..525aa2a632b2 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -7,6 +7,8 @@ * functionality: */ +#include <linux/rcupdate.h> +#include <linux/refcount.h> #include <linux/sched.h> #include <linux/uaccess.h> @@ -41,6 +43,7 @@ struct kernel_clone_args { void *fn_arg; struct cgroup *cgrp; struct css_set *cset; + unsigned int kill_seq; }; /* @@ -60,8 +63,9 @@ extern int lockdep_tasklist_lock_is_held(void); extern asmlinkage void schedule_tail(struct task_struct *prev); extern void init_idle(struct task_struct *idle, int cpu); -extern int sched_fork(unsigned long clone_flags, struct task_struct *p); -extern void sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs); +extern int sched_fork(u64 clone_flags, struct task_struct *p); +extern int sched_cgroup_fork(struct task_struct *p, struct kernel_clone_args *kargs); +extern void sched_cancel_fork(struct task_struct *p); extern void sched_post_fork(struct task_struct *p); extern void sched_dead(struct task_struct *p); @@ -105,11 +109,7 @@ int kernel_wait(pid_t pid, int *stat); extern void free_task(struct task_struct *tsk); /* sched_exec is called by processes performing an exec */ -#ifdef CONFIG_SMP extern void sched_exec(void); -#else -#define sched_exec() {} -#endif static inline struct task_struct *get_task_struct(struct task_struct *t) { @@ -117,6 +117,11 @@ static inline struct task_struct *get_task_struct(struct task_struct *t) return t; } +static inline struct task_struct *tryget_task_struct(struct task_struct *t) +{ + return refcount_inc_not_zero(&t->usage) ? t : NULL; +} + extern void __put_task_struct(struct task_struct *t); extern void __put_task_struct_rcu_cb(struct rcu_head *rhp); @@ -126,24 +131,17 @@ static inline void put_task_struct(struct task_struct *t) return; /* - * In !RT, it is always safe to call __put_task_struct(). - * Under RT, we can only call it in preemptible context. - */ - if (!IS_ENABLED(CONFIG_PREEMPT_RT) || preemptible()) { - static DEFINE_WAIT_OVERRIDE_MAP(put_task_map, LD_WAIT_SLEEP); - - lock_map_acquire_try(&put_task_map); - __put_task_struct(t); - lock_map_release(&put_task_map); - return; - } - - /* - * under PREEMPT_RT, we can't call put_task_struct + * Under PREEMPT_RT, we can't call __put_task_struct * in atomic context because it will indirectly - * acquire sleeping locks. + * acquire sleeping locks. The same is true if the + * current process has a mutex enqueued (blocked on + * a PI chain). * - * call_rcu() will schedule delayed_put_task_struct_rcu() + * In !RT, it is always safe to call __put_task_struct(). + * Though, in order to simplify the code, resort to the + * deferred call too. + * + * call_rcu() will schedule __put_task_struct_rcu_cb() * to be called in process context. * * __put_task_struct() is called when @@ -156,7 +154,7 @@ static inline void put_task_struct(struct task_struct *t) * * delayed_free_task() also uses ->rcu, but it is only called * when it fails to fork a process. Therefore, there is no - * way it can conflict with put_task_struct(). + * way it can conflict with __put_task_struct(). */ call_rcu(&t->rcu, __put_task_struct_rcu_cb); } @@ -212,9 +210,8 @@ static inline struct vm_struct *task_stack_vm_area(const struct task_struct *t) * pins the final release of task.io_context. Also protects ->cpuset and * ->cgroup.subsys[]. And ->vfork_done. And ->sysvshm.shm_clist. * - * Nests both inside and outside of read_lock(&tasklist_lock). - * It must not be nested with write_lock_irq(&tasklist_lock), - * neither inside nor outside. + * Nests inside of read_lock(&tasklist_lock). It must not be nested with + * write_lock_irq(&tasklist_lock), neither inside nor outside. */ static inline void task_lock(struct task_struct *p) { @@ -226,4 +223,6 @@ static inline void task_unlock(struct task_struct *p) spin_unlock(&p->alloc_lock); } +DEFINE_GUARD(task_lock, struct task_struct *, task_lock(_T), task_unlock(_T)) + #endif /* _LINUX_SCHED_TASK_H */ |