File 24231-waitqueue_Implement_wake_up_nroneall..patch of Package xen

changeset:   24231:2a81ce2b2b93
user:        Keir Fraser <keir@xen.org>
date:        Fri Nov 25 20:27:11 2011 +0000
files:       xen/common/wait.c xen/include/xen/wait.h
description:
waitqueue: Implement wake_up_{nr,one,all}.

Signed-off-by: Keir Fraser <keir@xen.org>


---
 xen/common/wait.c      |   14 ++++++++++++--
 xen/include/xen/wait.h |    6 ++++--
 2 files changed, 16 insertions(+), 4 deletions(-)

Index: xen-4.1.2-testing/xen/common/wait.c
===================================================================
--- xen-4.1.2-testing.orig/xen/common/wait.c
+++ xen-4.1.2-testing/xen/common/wait.c
@@ -87,13 +87,13 @@ void init_waitqueue_head(struct waitqueu
     INIT_LIST_HEAD(&wq->list);
 }
 
-void wake_up(struct waitqueue_head *wq)
+void wake_up_nr(struct waitqueue_head *wq, unsigned int nr)
 {
     struct waitqueue_vcpu *wqv;
 
     spin_lock(&wq->lock);
 
-    while ( !list_empty(&wq->list) )
+    while ( !list_empty(&wq->list) && nr-- )
     {
         wqv = list_entry(wq->list.next, struct waitqueue_vcpu, list);
         list_del_init(&wqv->list);
@@ -103,6 +103,16 @@ void wake_up(struct waitqueue_head *wq)
     spin_unlock(&wq->lock);
 }
 
+void wake_up_one(struct waitqueue_head *wq)
+{
+    wake_up_nr(wq, 1);
+}
+
+void wake_up_all(struct waitqueue_head *wq)
+{
+    wake_up_nr(wq, UINT_MAX);
+}
+
 #ifdef CONFIG_X86
 
 static void __prepare_to_wait(struct waitqueue_vcpu *wqv)
Index: xen-4.1.2-testing/xen/include/xen/wait.h
===================================================================
--- xen-4.1.2-testing.orig/xen/include/xen/wait.h
+++ xen-4.1.2-testing/xen/include/xen/wait.h
@@ -28,8 +28,10 @@ struct waitqueue_head {
 /* Dynamically initialise a waitqueue. */
 void init_waitqueue_head(struct waitqueue_head *wq);
 
-/* Wake all VCPUs waiting on specified waitqueue. */
-void wake_up(struct waitqueue_head *wq);
+/* Wake VCPU(s) waiting on specified waitqueue. */
+void wake_up_nr(struct waitqueue_head *wq, unsigned int nr);
+void wake_up_one(struct waitqueue_head *wq);
+void wake_up_all(struct waitqueue_head *wq);
 
 /* Wait on specified waitqueue until @condition is true. */
 #define wait_event(wq, condition)               \