diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2017-03-23 15:56:13 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-04-04 11:44:06 +0200 |
| commit | e0aad5b44ff5d28ac1d6ae70cdf84ca228e889dc (patch) | |
| tree | 5e15c53d3b2fa6096e14073a3f0140ca81aeeda4 /kernel/locking/rtmutex_common.h | |
| parent | b91473ff6e979c0028f02f90e40c844959c736d8 (diff) | |
| download | linux-e0aad5b44ff5d28ac1d6ae70cdf84ca228e889dc.tar.gz | |
rtmutex: Fix PI chain order integrity
rt_mutex_waiter::prio is a copy of task_struct::prio which is updated
during the PI chain walk, such that the PI chain order isn't messed up
by (asynchronous) task state updates.
Currently rt_mutex_waiter_less() uses task state for deadline tasks;
this is broken, since the task state can, as said above, change
asynchronously, causing the RB tree order to change without actual
tree update -> FAIL.
Fix this by also copying the deadline into the rt_mutex_waiter state
and updating it along with its prio field.
Ideally we would also force PI chain updates whenever DL tasks update
their deadline parameter, but for first approximation this is less
broken than it was.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: juri.lelli@arm.com
Cc: bigeasy@linutronix.de
Cc: xlpang@redhat.com
Cc: rostedt@goodmis.org
Cc: mathieu.desnoyers@efficios.com
Cc: jdesfossez@efficios.com
Cc: bristot@redhat.com
Link: http://lkml.kernel.org/r/20170323150216.403992539@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/locking/rtmutex_common.h')
| -rw-r--r-- | kernel/locking/rtmutex_common.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h index 9e36aeddce18..72ad45a9a794 100644 --- a/kernel/locking/rtmutex_common.h +++ b/kernel/locking/rtmutex_common.h @@ -34,6 +34,7 @@ struct rt_mutex_waiter { struct rt_mutex *deadlock_lock; #endif int prio; + u64 deadline; }; /* |