diff options
Diffstat (limited to 'include/linux/pid.h')
| -rw-r--r-- | include/linux/pid.h | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/include/linux/pid.h b/include/linux/pid.h new file mode 100644 index 00000000000..5b2fcb19d2d --- /dev/null +++ b/include/linux/pid.h @@ -0,0 +1,55 @@ +#ifndef _LINUX_PID_H +#define _LINUX_PID_H + +enum pid_type +{ + PIDTYPE_PID, + PIDTYPE_TGID, + PIDTYPE_PGID, + PIDTYPE_SID, + PIDTYPE_MAX +}; + +struct pid +{ + /* Try to keep pid_chain in the same cacheline as nr for find_pid */ + int nr; + struct hlist_node pid_chain; + /* list of pids with the same nr, only one of them is in the hash */ + struct list_head pid_list; +}; + +#define pid_task(elem, type) \ + list_entry(elem, struct task_struct, pids[type].pid_list) + +/* + * attach_pid() and detach_pid() must be called with the tasklist_lock + * write-held. + */ +extern int FASTCALL(attach_pid(struct task_struct *task, enum pid_type type, int nr)); + +extern void FASTCALL(detach_pid(struct task_struct *task, enum pid_type)); + +/* + * look up a PID in the hash table. Must be called with the tasklist_lock + * held. + */ +extern struct pid *FASTCALL(find_pid(enum pid_type, int)); + +extern int alloc_pidmap(void); +extern void FASTCALL(free_pidmap(int)); +extern void switch_exec_pids(struct task_struct *leader, struct task_struct *thread); + +#define do_each_task_pid(who, type, task) \ + if ((task = find_task_by_pid_type(type, who))) { \ + prefetch((task)->pids[type].pid_list.next); \ + do { + +#define while_each_task_pid(who, type, task) \ + } while (task = pid_task((task)->pids[type].pid_list.next,\ + type), \ + prefetch((task)->pids[type].pid_list.next), \ + hlist_unhashed(&(task)->pids[type].pid_chain)); \ + } \ + +#endif /* _LINUX_PID_H */ |