xnu-792.18.15.tar.gz

[apple/xnu.git] / osfmk / kern / wait_queue.h

diff --git a/osfmk/kern/wait_queue.h b/osfmk/kern/wait_queue.h
index 560b25325e0ad01bfaf3502f6ca51a19bac6d8a5..74c8fa6d7175a6c1494e8968a4d86764e7a3fb36 100644 (file)
--- a/osfmk/kern/wait_queue.h
+++ b/osfmk/kern/wait_queue.h
@@ -155,13 +155,24 @@ typedef struct wait_queue_link {
  * a problem with a thread lock, it normally times out at the wait
  * queue level first, hiding the real problem.
  */
  * a problem with a thread lock, it normally times out at the wait
  * queue level first, hiding the real problem.
  */

-#define wait_queue_lock(wq)    \
-       ((void) (!hw_lock_to(&(wq)->wq_interlock, LockTimeOut * 2) ? \
-                panic("wait queue deadlock - wq=0x%x, cpu=%d\n", \
-                      wq, cpu_number()) : 0))

 
 

-#define wait_queue_unlock(wq) \
-       (assert(wait_queue_held(wq)), hw_lock_unlock(&(wq)->wq_interlock))
+static inline void wait_queue_lock(wait_queue_t wq) {
+       if (!hw_lock_to(&(wq)->wq_interlock, LockTimeOut * 2))
+               panic("wait queue deadlock - wq=0x%x, cpu=%d\n", wq, cpu_number());
+}
+
+static inline void wait_queue_unlock(wait_queue_t wq) {
+       assert(wait_queue_held(wq));
+#if defined(__i386__)
+       /* On certain x86 systems, this spinlock is susceptible to
+        * lock starvation. Hence use an unlock variant which performs
+        * a cacheline flush to minimize cache affinity on acquisition.
+        */
+       i386_lock_unlock_with_flush(&(wq)->wq_interlock);
+#else
+        hw_lock_unlock(&(wq)->wq_interlock);
+#endif
+}

 
 #define wqs_lock(wqs)          wait_queue_lock(&(wqs)->wqs_wait_queue)
 #define wqs_unlock(wqs)                wait_queue_unlock(&(wqs)->wqs_wait_queue)
 
 #define wqs_lock(wqs)          wait_queue_lock(&(wqs)->wqs_wait_queue)
 #define wqs_unlock(wqs)                wait_queue_unlock(&(wqs)->wqs_wait_queue)