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-rw-r--r--include/linux/pid.h55
1 files changed, 55 insertions, 0 deletions
diff --git a/include/linux/pid.h b/include/linux/pid.h
new file mode 100644
index 000000000000..5b2fcb19d2da
--- /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 */