Index: sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c
===================================================================
--- sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c
+++ sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c
@@ -12048,7 +12048,6 @@
 	hrtime_t now;
 
 	ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
-	ASSERT(!(buf->dtb_flags & DTRACEBUF_RING));
 
 	cookie = dtrace_interrupt_disable();
 	now = dtrace_gethrtime();
@@ -14855,10 +14854,10 @@
 
 	if (which == DTRACEOPT_BUFSIZE) {
 		if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_RING)
-			flags |= DTRACEBUF_RING;
+			flags |= DTRACEBUF_RING | DTRACEBUF_NOSWITCH;
 
 		if (opt[DTRACEOPT_BUFPOLICY] == DTRACEOPT_BUFPOLICY_FILL)
-			flags |= DTRACEBUF_FILL;
+			flags |= DTRACEBUF_FILL | DTRACEBUF_NOSWITCH;
 
 		if (state != dtrace_anon.dta_state ||
 		    state->dts_activity != DTRACE_ACTIVITY_ACTIVE)