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authorSteven Rostedt <rostedt@goodmis.org>2012-03-01 13:55:33 -0500
committerSteven Rostedt <rostedt@rostedt.homelinux.com>2013-02-14 12:34:35 -0500
commita225f6fbe107241ee44f8cc7b90608968363c6eb (patch)
treeefe2679b2c56b5cc550e15e1ae76a9782cecb9be
parent94a16cf09f5856b19c05e91ac7cf8d48e35a80c3 (diff)
sched/rt: Fix wait_task_interactive() to test rt_spin_lock state
The wait_task_interactive() will have a task sleep waiting for another task to have a certain state. But it ignores the rt_spin_locks state and can return with an incorrect result if the task it is waiting for is blocked on a rt_spin_lock() and is waking up. The rt_spin_locks save the tasks state in the saved_state field and the wait_task_interactive() must also test that state. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Carsten Emde <C.Emde@osadl.org> Cc: John Kacur <jkacur@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Clark Williams <clark.williams@gmail.com> Cc: stable-rt@vger.kernel.org Link: http://lkml.kernel.org/r/20120301190345.979435764@goodmis.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--kernel/sched.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index 9a43d00c8ea6..ae081012cd9c 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2281,7 +2281,8 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
* is actually now running somewhere else!
*/
while (task_running(rq, p)) {
- if (match_state && unlikely(p->state != match_state))
+ if (match_state && unlikely(p->state != match_state)
+ && unlikely(p->saved_state != match_state))
return 0;
cpu_relax();
}
@@ -2296,7 +2297,8 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
running = task_running(rq, p);
on_rq = p->on_rq;
ncsw = 0;
- if (!match_state || p->state == match_state)
+ if (!match_state || p->state == match_state
+ || p->saved_state == match_state)
ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
task_rq_unlock(rq, p, &flags);