Eric Lee / smarc-fsl-linux-kernel

22 Jun, 2014

1 commit

  • 8930ed80f   rtmutex: Cleanup deadlock detector debug logic ... Browse Code »

    The conditions under which deadlock detection is conducted are unclear
    and undocumented.

    Add constants instead of using 0/1 and provide a selection function
    which hides the additional debug dependency from the calling code.

    Add comments where needed.

    Signed-off-by: Thomas Gleixner
    Cc: Peter Zijlstra
    Reviewed-by: Steven Rostedt
    Cc: Lai Jiangshan
    Link: http://lkml.kernel.org/r/20140522031949.947264874@linutronix.de
    Signed-off-by: Thomas Gleixner

    Thomas Gleixner
     

13 Jan, 2014

1 commit

  • fb00aca47   rtmutex: Turn the plist into an rb-tree ... Browse Code »

    Turn the pi-chains from plist to rb-tree, in the rt_mutex code,
    and provide a proper comparison function for -deadline and
    -priority tasks.

    This is done mainly because:
    - classical prio field of the plist is just an int, which might
    not be enough for representing a deadline;
    - manipulating such a list would become O(nr_deadline_tasks),
    which might be to much, as the number of -deadline task increases.

    Therefore, an rb-tree is used, and tasks are queued in it according
    to the following logic:
    - among two -priority (i.e., SCHED_BATCH/OTHER/RR/FIFO) tasks, the
    one with the higher (lower, actually!) prio wins;
    - among a -priority and a -deadline task, the latter always wins;
    - among two -deadline tasks, the one with the earliest deadline
    wins.

    Queueing and dequeueing functions are changed accordingly, for both
    the list of a task's pi-waiters and the list of tasks blocked on
    a pi-lock.

    Signed-off-by: Peter Zijlstra
    Signed-off-by: Dario Faggioli
    Signed-off-by: Juri Lelli
    Signed-off-again-by: Peter Zijlstra
    Link: http://lkml.kernel.org/r/1383831828-15501-10-git-send-email-juri.lelli@gmail.com
    Signed-off-by: Ingo Molnar

    Peter Zijlstra
     

06 Nov, 2013

1 commit