DTRACEBUF_RING
ASSERT(!(buf->dtb_flags & DTRACEBUF_RING));
if (!(buf->dtb_flags & (DTRACEBUF_RING | DTRACEBUF_FILL))) {
ASSERT(buf->dtb_flags & DTRACEBUF_RING);
if (buf->dtb_flags & DTRACEBUF_RING)
flags |= DTRACEBUF_RING;
if (buf->dtb_flags & (DTRACEBUF_RING | DTRACEBUF_FILL)) {