Index: kernel/arch/sparc64/src/proc/sun4u/scheduler.c
===================================================================
--- kernel/arch/sparc64/src/proc/sun4u/scheduler.c	(revision 0f4f1b286ec18fe5bc220bbc629fc26b6813d889)
+++ kernel/arch/sparc64/src/proc/sun4u/scheduler.c	(revision 286da52c77dc3bd30ef7b617138baded44d5dbb5)
@@ -76,4 +76,6 @@
 {
 	if (THREAD->uspace) {
+		asm volatile ("flushw");
+
 		/* sample the state of the userspace window buffer */
 		THREAD->arch.uspace_window_buffer =
Index: kernel/arch/sparc64/src/proc/sun4v/scheduler.c
===================================================================
--- kernel/arch/sparc64/src/proc/sun4v/scheduler.c	(revision 0f4f1b286ec18fe5bc220bbc629fc26b6813d889)
+++ kernel/arch/sparc64/src/proc/sun4v/scheduler.c	(revision 286da52c77dc3bd30ef7b617138baded44d5dbb5)
@@ -68,4 +68,6 @@
 {
 	if (THREAD->uspace) {
+		asm volatile ("flushw");
+
 		/* sample the state of the userspace window buffer */
 		THREAD->arch.uspace_window_buffer =