On Thu, Nov 03, 2011 at 01:21:25PM +0100, Camiel Dobbelaar wrote:
No one interested in this one? I have another bridge speedup diff after
this.
Ugh, forgot to answer on that one. I'm against overusing the M_PROTO1
flag. Keep in mind that M_PROTO1 is just a flag whereas the mbuf_tag is a
pointer to the ifp. So M_PROTO1 does not scale if there are multiple
bridges involved in forwarding a packet. M_PROTO1 is only OK to use when
the flag is cleared when leaving the protocol. E.g. it can be used when a
hint needs to be passed accross an ifq.
--
:wq Claudio
On Fri, 28 Oct 2011, Camiel Dobbelaar wrote:
M_PROTO1 is used by if_bridge on the input path. On the output path it's
used now only by if_bridge for if_gif. I think we can use it generically
to mark packets as processed by bridge in the output path.
The diff simplifies things and avoids mtag checking and allocation so is
more efficient too.
The old code checks if a packet has passed the _same_ bridge already, but
as an interface can only be a member of one bridge I think the flag is
sufficient.
It looks like the only other user of M_PROTO1 is netbt/hci_link.c, but
that can be fixed if the diff is acceptable otherwise.
Tested lightly in a bridge/gif setup, but could use some more testing.
(especially with ipsec in the mix too)
Index: if_bridge.c
===
RCS file: /cvs/src/sys/net/if_bridge.c,v
retrieving revision 1.193
diff -u -p -r1.193 if_bridge.c
--- if_bridge.c 4 Jul 2011 06:54:49 - 1.193
+++ if_bridge.c 28 Oct 2011 17:55:04 -
@@ -2813,9 +2813,8 @@ bridge_ifenqueue(struct bridge_softc *sc
#if NGIF 0
/* Packet needs etherip encapsulation. */
if (ifp-if_type == IFT_GIF) {
- m-m_flags |= M_PROTO1;
-
/* Count packets input into the gif from outside */
+ /* XXX do this in if_gif? */
ifp-if_ipackets++;
ifp-if_ibytes += m-m_pkthdr.len;
}
@@ -2844,6 +2843,7 @@ bridge_ifenqueue(struct bridge_softc *sc
}
#endif
len = m-m_pkthdr.len;
+ m-m_flags |= M_PROTO1;
mflags = m-m_flags;
IFQ_ENQUEUE(ifp-if_snd, m, NULL, error);
if (error) {
Index: if_ethersubr.c
===
RCS file: /cvs/src/sys/net/if_ethersubr.c,v
retrieving revision 1.151
diff -u -p -r1.151 if_ethersubr.c
--- if_ethersubr.c 9 Jul 2011 00:47:18 - 1.151
+++ if_ethersubr.c 28 Oct 2011 17:55:04 -
@@ -382,40 +382,8 @@ ether_output(ifp0, m0, dst, rt0)
* Interfaces that are bridge members need special handling
* for output.
*/
- if (ifp-if_bridge) {
- struct m_tag *mtag;
-
- /*
-* Check if this packet has already been sent out through
-* this bridge, in which case we simply send it out
-* without further bridge processing.
-*/
- for (mtag = m_tag_find(m, PACKET_TAG_BRIDGE, NULL); mtag;
- mtag = m_tag_find(m, PACKET_TAG_BRIDGE, mtag)) {
-#ifdef DEBUG
- /* Check that the information is there */
- if (mtag-m_tag_len != sizeof(caddr_t)) {
- error = EINVAL;
- goto bad;
- }
-#endif
- if (!bcmp(ifp-if_bridge, mtag + 1, sizeof(caddr_t)))
- break;
- }
- if (mtag == NULL) {
- /* Attach a tag so we can detect loops */
- mtag = m_tag_get(PACKET_TAG_BRIDGE, sizeof(caddr_t),
- M_NOWAIT);
- if (mtag == NULL) {
- error = ENOBUFS;
- goto bad;
- }
- bcopy(ifp-if_bridge, mtag + 1, sizeof(caddr_t));
- m_tag_prepend(m, mtag);
- error = bridge_output(ifp, m, NULL, NULL);
- return (error);
- }
- }
+ if (ifp-if_bridge !(m-m_flags M_PROTO1))
+ return (bridge_output(ifp, m, NULL, NULL));
#endif
mflags = m-m_flags;
len = m-m_pkthdr.len;
