M_TCPFSB
M_TCPFSB, M_NOWAIT|M_ZERO);
#define M_TCPFSB __CONCAT(M_TCPFSB, STACKNAME)
rack->r_ctl.tqh = malloc(sizeof(struct tailq_hash), M_TCPFSB, M_NOWAIT);
MALLOC_DEFINE(M_TCPFSB, "tcp_fsb_" __XSTRING(STACKNAME), "TCP fast send block");
free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
free(rack->r_ctl.tqh, M_TCPFSB);