2013-05-15 09:05:25

by Juri Lelli

[permalink] [raw]
Subject: [PATCH] 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 <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Clark Williams <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Peter Zijlstra <[email protected]>
---
kernel/rtmutex.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 1e09308..0dd6aec 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,
--
1.7.9.5


Subject: [tip:core/locking] rtmutex: Document rt_mutex_adjust_prio_chain()

Commit-ID: 0c1061733aa0303e6536c0bc7f86d68f5eb55446
Gitweb: http://git.kernel.org/tip/0c1061733aa0303e6536c0bc7f86d68f5eb55446
Author: Juri Lelli <[email protected]>
AuthorDate: Wed, 15 May 2013 11:04:10 +0200
Committer: Ingo Molnar <[email protected]>
CommitDate: Tue, 28 May 2013 09:23:52 +0200

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 <[email protected]>
Cc: Clark Williams <[email protected]>
Cc: Steven Rostedt <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
kernel/rtmutex.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index 1e09308..0dd6aec 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,