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authorSteven Rostedt <rostedt@goodmis.org>2012-03-01 13:55:33 -0500
committerSteven Rostedt <rostedt@goodmis.org>2012-03-09 10:26:26 -0500
commitd45d32ba63c6381f255ffcff10091e18df5e1e35 (patch)
tree48b5ddea13e320eaeb0cfd8e0bf15119911e6264
parentcac5fca5e1c9c5d40a7a91f2ce4d911d6e964c80 (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 e5ef7a866480..df3048139d1b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2284,7 +2284,8 @@ 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();
}
@@ -2299,7 +2300,8 @@ 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);