• Thomas Gleixner's avatar
    rtmutex: Handle deadlock detection smarter · 3d5c9340
    Thomas Gleixner authored
    Even in the case when deadlock detection is not requested by the
    caller, we can detect deadlocks. Right now the code stops the lock
    chain walk and keeps the waiter enqueued, even on itself. Silly not to
    yell when such a scenario is detected and to keep the waiter enqueued.
    Return -EDEADLK unconditionally and handle it at the call sites.
    The futex calls return -EDEADLK. The non futex ones dequeue the
    waiter, throw a warning and put the task into a schedule loop.
    Tagged for stable as it makes the code more robust.
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Cc: Steven Rostedt <rostedt@goodmis.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Brad Mouring <bmouring@ni.com>
    Link: http://lkml.kernel.org/r/20140605152801.836501969@linutronix.de
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
rtmutex.h 1.22 KB