linux/kernel/locking
Peter Zijlstra fb00aca474 rtmutex: Turn the plist into an rb-tree
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 <peterz@infradead.org>
Signed-off-by: Dario Faggioli <raistlin@linux.it>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-again-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1383831828-15501-10-git-send-email-juri.lelli@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-01-13 13:41:50 +01:00
..
lglock.c locking: Move the lglocks code to kernel/locking/ 2013-11-06 09:24:20 +01:00
lockdep_internals.h
lockdep_proc.c lockdep/proc: Fix lock-time avg computation 2013-11-11 12:41:34 +01:00
lockdep_states.h
lockdep.c locking/lockdep: Mark __lockdep_count_forward_deps() as static 2013-11-13 13:50:17 +01:00
Makefile locking: Move the percpu-rwsem code to kernel/locking/ 2013-11-06 09:24:22 +01:00
mutex-debug.c
mutex-debug.h
mutex.c locking/doc: Update references to kernel/mutex.c 2013-11-11 12:41:33 +01:00
mutex.h
percpu-rwsem.c locking: Move the percpu-rwsem code to kernel/locking/ 2013-11-06 09:24:22 +01:00
rtmutex_common.h rtmutex: Turn the plist into an rb-tree 2014-01-13 13:41:50 +01:00
rtmutex-debug.c rtmutex: Turn the plist into an rb-tree 2014-01-13 13:41:50 +01:00
rtmutex-debug.h locking: Move the rtmutex code to kernel/locking/ 2013-11-06 09:23:59 +01:00
rtmutex-tester.c locking: Move the rtmutex code to kernel/locking/ 2013-11-06 09:23:59 +01:00
rtmutex.c rtmutex: Turn the plist into an rb-tree 2014-01-13 13:41:50 +01:00
rtmutex.h locking: Move the rtmutex code to kernel/locking/ 2013-11-06 09:23:59 +01:00
rwsem-spinlock.c locking: Move the rwsem code to kernel/locking/ 2013-11-06 09:24:18 +01:00
rwsem-xadd.c locking: Move the rwsem code to kernel/locking/ 2013-11-06 09:24:18 +01:00
rwsem.c locking: Move the rwsem code to kernel/locking/ 2013-11-06 09:24:18 +01:00
semaphore.c locking: Move the semaphore core to kernel/locking/ 2013-11-06 07:55:22 +01:00
spinlock_debug.c locking: Move the spinlock code to kernel/locking/ 2013-11-06 07:55:21 +01:00
spinlock.c locking: Move the spinlock code to kernel/locking/ 2013-11-06 07:55:21 +01:00