DTRACEBUF_NOSWITCH
ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
if (flags & DTRACEBUF_NOSWITCH)
ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));
flags |= DTRACEBUF_NOSWITCH;
ASSERT(!(buf->dtb_flags & DTRACEBUF_NOSWITCH));