PIPE_BUF
sysmsg->sysmsg_result = PIPE_BUF;
ready = kn->kn_data >= PIPE_BUF;
if ((space < uio->uio_resid) && (orig_resid <= PIPE_BUF))
(orig_resid <= PIPE_BUF)) {
if ((space < uio->uio_resid) && (orig_resid <= PIPE_BUF))
*ap->a_retval = PIPE_BUF;
*ap->a_retval = PIPE_BUF;
wso->so_snd.ssb_lowat = PIPE_BUF;
*ap->a_retval = PIPE_BUF;
*ap->a_retval = PIPE_BUF;
*retval = PIPE_BUF;