[PATCH 2/5] pid: Add macros for interating through tasks by type.

[ebiederm@xmission.com (Eric W. Biederman)]

Currently do_each_task_pid/while_each_task_pid make it
possible to iterate through each task of a group of
processes given the pid of the group.

do_each_task/while_each_task do the same thing but assume
you are atarting with the first task of a process group.
This is needed so we can start with a task_ref instead
of a pid.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>


---

 include/linux/pid.h |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

34e71e62a13a78350239c18e3e3c31e79593380f
diff --git a/include/linux/pid.h b/include/linux/pid.h
index e206149..7fa9b2e 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -54,4 +54,16 @@ extern void switch_exec_pids(struct task
 			hlist_unhashed(&(task)->pids[type].pid_chain));	\
 	}								\
 
+#define do_each_task(task, type)					\
+	if (task) {					\
+		prefetch((task)->pids[type].pid_list.next);	\
+		do {
+
+#define while_each_task(task, type)					\
+		} 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 */
-- 
1.1.5.g3480