sx_xholder
#define rw_owner(lock) sx_xholder(lock)
if (unlikely(sx_xholder(&lock->sx) == curthread))
sx_xholder(sx) != curthread)))
if (sx_xholder(sx) != curthread)
if (sx_xholder(sx) == curthread)
td = sx_xholder(sx);
*ownerp = sx_xholder(sx);
MPASS(sx_xholder(&cp->co_interlock) == curthread);
MPASS(sx_xholder(&cp->co_interlock) == curthread);
MPASS(sx_xholder(&cp->co_interlock) == curthread);