On Fri, Jan 16, 2015 at 11:48:46AM -0500, Steven Rostedt wrote:

quoted

@@ -971,8 +971,8 @@
 	kvm_mips_callbacks->queue_timer_int(vcpu);
 
 	vcpu->arch.wait = 0;
-	if (waitqueue_active(&vcpu->wq)) {
-		wake_up_interruptible(&vcpu->wq);
+	if (swaitqueue_active(&vcpu->wq)) {
+		swait_wake_nterruptible(&vcpu->wq);

Sure you compiled this patch?

Only x86.

quoted

Index: linux-stable-rt/arch/powerpc/include/asm/kvm_host.h
===================================================================

--- linux-stable-rt.orig/arch/powerpc/include/asm/kvm_host.h	2014-11-25 14:13:39.193899944 -0200
+++ linux-stable-rt/arch/powerpc/include/asm/kvm_host.h	2014-11-25 14:14:38.621810091 -0200

@@ -295,7 +295,7 @@
 	u8 in_guest;
 	struct list_head runnable_threads;
 	spinlock_t lock;
-	wait_queue_head_t wq;
+	struct swait_head wq;
 	u64 stolen_tb;
 	u64 preempt_tb;
 	struct kvm_vcpu *runner;

@@ -612,7 +612,7 @@
 	u8 prodded;
 	u32 last_inst;
 
-	wait_queue_head_t *wqp;
+	struct swait_head *wqp;
 	struct kvmppc_vcore *vcore;
 	int ret;
 	int trap;

Index: linux-stable-rt/arch/powerpc/kvm/book3s_hv.c
===================================================================

--- linux-stable-rt.orig/arch/powerpc/kvm/book3s_hv.c	2014-11-25 14:13:39.195899942 -0200
+++ linux-stable-rt/arch/powerpc/kvm/book3s_hv.c	2014-11-25 14:14:38.625810085 -0200

@@ -74,11 +74,11 @@
 {
 	int me;
 	int cpu = vcpu->cpu;
-	wait_queue_head_t *wqp;
+	struct swait_head *wqp;
 
 	wqp = kvm_arch_vcpu_wq(vcpu);
-	if (waitqueue_active(wqp)) {
-		wake_up_interruptible(wqp);
+	if (swaitqueue_active(wqp)) {
+		swait_wake_interruptible(wqp);
 		++vcpu->stat.halt_wakeup;
 	}
 

@@ -583,8 +583,8 @@
 		tvcpu->arch.prodded = 1;
 		smp_mb();
 		if (vcpu->arch.ceded) {
-			if (waitqueue_active(&vcpu->wq)) {
-				wake_up_interruptible(&vcpu->wq);
+			if (swaitqueue_active(&vcpu->wq)) {
+				swait_wake_interruptible(&vcpu->wq);
 				vcpu->stat.halt_wakeup++;
 			}
 		}

@@ -1199,7 +1199,7 @@
 		if (vcore) {
 			INIT_LIST_HEAD(&vcore->runnable_threads);
 			spin_lock_init(&vcore->lock);
-			init_waitqueue_head(&vcore->wq);
+			init_swait_head(&vcore->wq);
 			vcore->preempt_tb = TB_NIL;
 			vcore->lpcr = kvm->arch.lpcr;
 			vcore->first_vcpuid = core * threads_per_core;

@@ -1566,13 +1566,13 @@
  */
 static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
 {
-	DEFINE_WAIT(wait);
+	DEFINE_SWAITER(wait);
 
-	prepare_to_wait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
+	swait_prepare(&vc->wq, &wait, TASK_INTERRUPTIBLE);
 	vc->vcore_state = VCORE_SLEEPING;
 	spin_unlock(&vc->lock);
 	schedule();
-	finish_wait(&vc->wq, &wait);
+	swait_finish(&vc->wq, &wait);
 	spin_lock(&vc->lock);
 	vc->vcore_state = VCORE_INACTIVE;
 }

@@ -1613,7 +1613,7 @@
 			kvmppc_create_dtl_entry(vcpu, vc);
 			kvmppc_start_thread(vcpu);
 		} else if (vc->vcore_state == VCORE_SLEEPING) {
-			wake_up(&vc->wq);
+			swait_wake(&vc->wq);

I notice everywhere you have a swait_wake_interruptible() but here. Is
there a reason why?

IIRC, Peter wants to make swait wakeup usage homogenous. That is, you
either sleep in an interruptible state, or you don't. You can't mix and
match it.

IIUC there is only one waiter on this waitqueue at any given time.

Paul is that correct?