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authorDavidlohr Bueso <dave@stgolabs.net>2017-09-08 16:15:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-08 18:26:49 -0700
commita23ba907d5e65d6aeea3e59c82fda9cd206a7aad (patch)
treea0bd42b27596cf758517fa004d1d8681a7eef932 /include
parent2161573ecd6931565936cb66793b2d2bf805c088 (diff)
locking/rtmutex: replace top-waiter and pi_waiters leftmost caching
... with the generic rbtree flavor instead. No changes in semantics whatsoever. Link: http://lkml.kernel.org/r/20170719014603.19029-10-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/init_task.h5
-rw-r--r--include/linux/rtmutex.h11
-rw-r--r--include/linux/sched.h3
3 files changed, 8 insertions, 11 deletions
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 0e849715e5be..3c07ace5b431 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -175,9 +175,8 @@ extern struct cred init_cred;
#ifdef CONFIG_RT_MUTEXES
# define INIT_RT_MUTEXES(tsk) \
- .pi_waiters = RB_ROOT, \
- .pi_top_task = NULL, \
- .pi_waiters_leftmost = NULL,
+ .pi_waiters = RB_ROOT_CACHED, \
+ .pi_top_task = NULL,
#else
# define INIT_RT_MUTEXES(tsk)
#endif
diff --git a/include/linux/rtmutex.h b/include/linux/rtmutex.h
index 44fd002f7cd5..53fcbe9de7fd 100644
--- a/include/linux/rtmutex.h
+++ b/include/linux/rtmutex.h
@@ -22,18 +22,17 @@ extern int max_lock_depth; /* for sysctl */
* The rt_mutex structure
*
* @wait_lock: spinlock to protect the structure
- * @waiters: rbtree root to enqueue waiters in priority order
- * @waiters_leftmost: top waiter
+ * @waiters: rbtree root to enqueue waiters in priority order;
+ * caches top-waiter (leftmost node).
* @owner: the mutex owner
*/
struct rt_mutex {
raw_spinlock_t wait_lock;
- struct rb_root waiters;
- struct rb_node *waiters_leftmost;
+ struct rb_root_cached waiters;
struct task_struct *owner;
#ifdef CONFIG_DEBUG_RT_MUTEXES
int save_state;
- const char *name, *file;
+ const char *name, *file;
int line;
void *magic;
#endif
@@ -84,7 +83,7 @@ do { \
#define __RT_MUTEX_INITIALIZER(mutexname) \
{ .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \
- , .waiters = RB_ROOT \
+ , .waiters = RB_ROOT_CACHED \
, .owner = NULL \
__DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
__DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)}
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 68b38335d33c..92fb8dd5a9e4 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -812,8 +812,7 @@ struct task_struct {
#ifdef CONFIG_RT_MUTEXES
/* PI waiters blocked on a rt_mutex held by this task: */
- struct rb_root pi_waiters;
- struct rb_node *pi_waiters_leftmost;
+ struct rb_root_cached pi_waiters;
/* Updated under owner's pi_lock and rq lock */
struct task_struct *pi_top_task;
/* Deadlock detection and priority inheritance handling: */