timerqueue: Let timerqueue_add/del return information

The hrtimer code is interested whether the added timer is the first
one to expire and whether the removed timer was the last one in the
tree. The add/del routines have that information already. So we can
return it right away instead of reevaluating it at the call site.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20150414203501.579063647@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/include/linux/timerqueue.h b/include/linux/timerqueue.h
index a520fd70a59f371f40a34f79e883dcf7b32c23f7..7eec17ad7fa195bba39c06e44817ef3f3a1b0402 100644 (file)
--- a/include/linux/timerqueue.h
+++ b/include/linux/timerqueue.h
@@ -16,10 +16,10 @@ struct timerqueue_head {
 };
 
 
-extern void timerqueue_add(struct timerqueue_head *head,
-                               struct timerqueue_node *node);
-extern void timerqueue_del(struct timerqueue_head *head,
-                               struct timerqueue_node *node);
+extern bool timerqueue_add(struct timerqueue_head *head,
+                          struct timerqueue_node *node);
+extern bool timerqueue_del(struct timerqueue_head *head,
+                          struct timerqueue_node *node);
 extern struct timerqueue_node *timerqueue_iterate_next(
                                                struct timerqueue_node *node);
 

diff --git a/lib/timerqueue.c b/lib/timerqueue.c
index a382e4a326091691a617a7c3387a09c813c50792..782ae8ca2c06f2b3439b10592cef6a43c31223cd 100644 (file)
--- a/lib/timerqueue.c
+++ b/lib/timerqueue.c
@@ -36,7 +36,7 @@
  * Adds the timer node to the timerqueue, sorted by the
  * node's expires value.
  */
-void timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node)
+bool timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node)
 {
        struct rb_node **p = &head->head.rb_node;
        struct rb_node *parent = NULL;
@@ -56,8 +56,11 @@ void timerqueue_add(struct timerqueue_head *head, struct timerqueue_node *node)
        rb_link_node(&node->node, parent, p);
        rb_insert_color(&node->node, &head->head);
 
-       if (!head->next || node->expires.tv64 < head->next->expires.tv64)
+       if (!head->next || node->expires.tv64 < head->next->expires.tv64) {
                head->next = node;
+               return true;
+       }
+       return false;
 }
 EXPORT_SYMBOL_GPL(timerqueue_add);
 
@@ -69,7 +72,7 @@ EXPORT_SYMBOL_GPL(timerqueue_add);
  *
  * Removes the timer node from the timerqueue.
  */
-void timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node)
+bool timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node)
 {
        WARN_ON_ONCE(RB_EMPTY_NODE(&node->node));
 
@@ -82,6 +85,7 @@ void timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node)
        }
        rb_erase(&node->node, &head->head);
        RB_CLEAR_NODE(&node->node);
+       return head->next != NULL;
 }
 EXPORT_SYMBOL_GPL(timerqueue_del);