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authorJuri Lelli <juri.lelli@gmail.com>2013-05-15 11:04:10 +0200
committerIngo Molnar <mingo@kernel.org>2013-05-28 09:23:52 +0200
commit0c1061733aa0303e6536c0bc7f86d68f5eb55446 (patch)
treefc5b4530d524e71c889aac367530f678c4c71168 /kernel/rtmutex.c
parent4eedb77a9cd8f2e68b31c8b9a20524a50727c16f (diff)
downloadlwn-0c1061733aa0303e6536c0bc7f86d68f5eb55446.tar.gz
lwn-0c1061733aa0303e6536c0bc7f86d68f5eb55446.zip
rtmutex: Document rt_mutex_adjust_prio_chain()
Parameters and usage of rt_mutex_adjust_prio_chain() are already documented in Documentation/rt-mutex-design.txt. However, since this function is called from several paths with different semantics (related to the arguments), it is handy to have a quick reference directly in the code. Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Cc: Clark Williams <williams@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1368608650-7935-1-git-send-email-juri.lelli@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/rtmutex.c')
-rw-r--r--kernel/rtmutex.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 1e09308bf2a1..0dd6aec1cb6a 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -145,6 +145,19 @@ int max_lock_depth = 1024;
/*
* Adjust the priority chain. Also used for deadlock detection.
* Decreases task's usage by one - may thus free the task.
+ *
+ * @task: the task owning the mutex (owner) for which a chain walk is probably
+ * needed
+ * @deadlock_detect: do we have to carry out deadlock detection?
+ * @orig_lock: the mutex (can be NULL if we are walking the chain to recheck
+ * things for a task that has just got its priority adjusted, and
+ * is waiting on a mutex)
+ * @orig_waiter: rt_mutex_waiter struct for the task that has just donated
+ * its priority to the mutex owner (can be NULL in the case
+ * depicted above or if the top waiter is gone away and we are
+ * actually deboosting the owner)
+ * @top_task: the current top waiter
+ *
* Returns 0 or -EDEADLK.
*/
static int rt_mutex_adjust_prio_chain(struct task_struct *task,