[src/trunk]: src/sys/netinet optimize mbuf allocation for ip/tcp/tcpopt part.

[itojun <itojun%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e60a6862e744
branches:  trunk
changeset: 481903:e60a6862e744
user:      itojun <itojun%NetBSD.org@localhost>
date:      Wed Feb 09 00:50:40 2000 +0000

description:
optimize mbuf allocation for ip/tcp/tcpopt part.

diffstat:

 sys/netinet/tcp_output.c |  10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diffs (38 lines):

diff -r 378877a3aa16 -r e60a6862e744 sys/netinet/tcp_output.c
--- a/sys/netinet/tcp_output.c  Wed Feb 09 00:33:03 2000 +0000
+++ b/sys/netinet/tcp_output.c  Wed Feb 09 00:50:40 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tcp_output.c,v 1.53 1999/12/13 15:17:20 itojun Exp $   */
+/*     $NetBSD: tcp_output.c,v 1.54 2000/02/09 00:50:40 itojun Exp $   */
 
 /*
 %%% portions-copyright-nrl-95
@@ -682,7 +682,9 @@
                m->m_data -= hdrlen;
 #else
                MGETHDR(m, M_DONTWAIT, MT_HEADER);
-               if (m != NULL) {
+               if (m != NULL &&
+                   (max_linkhdr + hdrlen > MHLEN ||
+                    max_linkhdr + hdrlen + len <= MCLBYTES)) {
                        MCLGET(m, M_DONTWAIT);
                        if ((m->m_flags & M_EXT) == 0) {
                                m_freem(m);
@@ -695,7 +697,7 @@
                }
                m->m_data += max_linkhdr;
                m->m_len = hdrlen;
-               if (len <= MCLBYTES - hdrlen - max_linkhdr) {
+               if (len <= M_TRAILINGSPACE(m)) {
                        m_copydata(so->so_snd.sb_mb, off, (int) len,
                            mtod(m, caddr_t) + hdrlen);
                        m->m_len += len;
@@ -727,7 +729,7 @@
                        tcpstat.tcps_sndwinup++;
 
                MGETHDR(m, M_DONTWAIT, MT_HEADER);
-               if (m != NULL) {
+               if (m != NULL && max_linkhdr + hdrlen > MHLEN) {
                        MCLGET(m, M_DONTWAIT);
                        if ((m->m_flags & M_EXT) == 0) {
                                m_freem(m);