ipc/mqueue.c: have RT tasks queue in by priority in wq_add()

Previous behavior added tasks to the work queue using the static_prio
value instead of the dynamic priority value in prio.  This caused RT tasks
to be added to the work queue in a FIFO manner rather than by priority.
Normal tasks were handled by priority.

This fix utilizes the dynamic priority of the task to ensure that both RT
and normal tasks are added to the work queue in priority order.  Utilizing
the dynamic priority (prio) rather than the base priority (normal_prio)
was chosen to ensure that if a task had a boosted priority when it was
added to the work queue, it would be woken sooner to to ensure that it
releases any other locks it may be holding in a more timely manner.  It is
understood that the task could have a lower priority when it wakes than
when it was added to the queue in this (unlikely) case.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Jonathan Haws <[email protected]>
Reviewed-by: Steven Rostedt (VMware) <[email protected]>
Reviewed-by: Davidlohr Bueso <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Deepa Dinamani <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Manfred Spraul <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 1 insertions, 1 deletions

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index 690ae6665500..360e564ae7d1 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -596,7 +596,7 @@ static void wq_add(struct mqueue_inode_info *info, int sr,
 	ewp->task = current;
 
 	list_for_each_entry(walk, &info->e_wait_q[sr].list, list) {
-		if (walk->task->static_prio <= current->static_prio) {
+		if (walk->task->prio <= current->prio) {
 			list_add_tail(&ewp->list, &walk->list);
 			return;
 		}