History log of /kernel/locking/rtmutex_common.h
Revision Date Author Comments
8930ed80f970a90a795239e7415c9b0e6f964649 22-May-2014 Thomas Gleixner <tglx@linutronix.de> rtmutex: Cleanup deadlock detector debug logic

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 <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/20140522031949.947264874@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
c051b21f71d1ffdfd7ad406a1ef5ede5e5f974c5 22-May-2014 Thomas Gleixner <tglx@linutronix.de> rtmutex: Confine deadlock logic to futex

The deadlock logic is only required for futexes.

Remove the extra arguments for the public functions and also for the
futex specific ones which get always called with deadlock detection
enabled.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
2d3d891d3344159d5b452a645e355bbe29591e8b 07-Nov-2013 Dario Faggioli <raistlin@linux.it> sched/deadline: Add SCHED_DEADLINE inheritance logic

Some method to deal with rt-mutexes and make sched_dl interact with
the current PI-coded is needed, raising all but trivial issues, that
needs (according to us) to be solved with some restructuring of
the pi-code (i.e., going toward a proxy execution-ish implementation).

This is under development, in the meanwhile, as a temporary solution,
what this commits does is:

- ensure a pi-lock owner with waiters is never throttled down. Instead,
when it runs out of runtime, it immediately gets replenished and it's
deadline is postponed;

- the scheduling parameters (relative deadline and default runtime)
used for that replenishments --during the whole period it holds the
pi-lock-- are the ones of the waiting task with earliest deadline.

Acting this way, we provide some kind of boosting to the lock-owner,
still by using the existing (actually, slightly modified by the previous
commit) pi-architecture.

We would stress the fact that this is only a surely needed, all but
clean solution to the problem. In the end it's only a way to re-start
discussion within the community. So, as always, comments, ideas, rants,
etc.. are welcome! :-)

Signed-off-by: Dario Faggioli <raistlin@linux.it>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
[ Added !RT_MUTEXES build fix. ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1383831828-15501-11-git-send-email-juri.lelli@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
fb00aca474405f4fa8a8519c3179fed722eabd83 07-Nov-2013 Peter Zijlstra <peterz@infradead.org> 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>
1696a8bee390929fed05c6297164816ae2ced280 31-Oct-2013 Peter Zijlstra <peterz@infradead.org> locking: Move the rtmutex code to kernel/locking/

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-p9ijt8div0hwldexwfm4nlhj@git.kernel.org
[ Fixed build failure in kernel/rcu/tree_plugin.h. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>